Chesapeake and Ohio Canal
The Chesapeake and Ohio Canal, abbreviated as the C&O Canal, and occasionally referred to as the "Grand Old Ditch," operated from 1831 until 1924 parallel to the Potomac River in Maryland from Cumberland, Maryland, to Washington, D.C. The total length of the canal is about 184.5 miles (296.9 km). The elevation change of 605 ft (184 m) was accommodated with 74 canal locks. To enable the canal to cross relatively small streams, over 150 culverts were built. The crossing of major streams required the construction of 11 aqueducts. The canal also extends through the 3,118 ft (950 m) Paw Paw Tunnel. The principal cargo in the latter years was coal from the Allegheny Mountains. The canal way is now maintained as a park, with a linear trail following the old towpath, the Chesapeake and Ohio Canal National Historical Park.
Early river projects
After the American Revolutionary War, George Washington was the chief advocate of using waterways to connect the Eastern Seaboard to the Great Lakes and the Ohio River. Washington founded the Potowmack Company in 1785 to make navigability improvements to the Potomac River. The Patowmack Company built 5 of skirting canals around the major falls: Little Falls (which was later incorporated in the C&O Canal), Great Falls skirting canal in Virginia, Seneca Falls (opposite Violette's lock), Payne's Falls of the Shenendoah, and House's Falls near Harpers Ferry. When completed, it allowed boats and rafts to float downstream towards Georgetown. Going upstream was a bit harder. Slim boats could be slowly polled upriver (using poles). The completion of the Erie Canal worried southern traders that their business might be threatened by the northern canal; plans for a canal linking the Ohio and Chesapeake were drawn up as early as 1820.
"Gondolas" were log rafts, 60 by 10 feet, and upon finishing the trip, the owners usually sold them for wood, and returned upstream on foot. "Sharpers" were flat bottomed boats on this canal, 60 feet by 7 feet, and they too, were polled, but were only usable when the river was high (flooding), only about 45 days per year.
Building the canal
Plans for the Canal
The canal was charted on March 5, 1835 by President Monroe. The plan was to build it in two sections, the eastern section from the tidewater of Washington DC to Cumberland, Maryland, and the western section over the Allegheny mountains to the Ohio river or one of its tributaries. The canal company was to be free from taxation, and had to have 100 miles in use in 5 years, and complete the canal in 12 years. The canal was planned to have a 2 mph water current downstream, which not only would feed the canal, but also help the mules pull loaded boats. The eastern section was the only part of the canal to be completed 
The planned C&O Canal route to navigable waters of the Mississippi watershed would have followed the North Branch Potomac River west from Cumberland to the Savage River. Via the Savage, the canal would have crossed the Eastern Continental Divide at the gap between the Savage and Backbone Mountains near where present day O'Brien Road intersects Maryland Route 495, then via the valley of present day Deep Creek Lake, followed the Youghiogheny River to navigable waters.]]
In 1824, the holdings of the "Patowmack Company" were ceded to the Chesapeake and Ohio Company. By 1825, the Canal Company was authorized by an act of the General Assembly of Maryland in the amount of subscriptions of $500,000 authorized by the act of incorporation paved the way for future investments and loans. According to future historians (J. Thomas Scharf, "History of Baltimore City and County", published 1881, reprinted 1971), those financial resources were expended until unfortunately the State had prostrated itself on its own credit.
Benjamin Wright, formerly Chief Engineer of the Erie Canal, was named Chief Engineer of this new effort, and construction began with a groundbreaking ceremony near Georgetown near the location of Lock 6 (close to the upstream end of the Little Falls skirting canal), on the Fourth of July, (Independence Day), 1828, by sixth President of the United States John Quincy Adams. On the same day, the little more than one-year old Baltimore and Ohio Railroad also set its "First Stone" with the aging, sole surviving Signer of the Declaration of Independence, Charles Carroll of Carrollton.
At the time of this ground breaking, there was still some argument over the eastern end of the canal. The directors thought that Little Falls (at the downstream end of the Patowmack Little Falls Skirting Canal) was sufficient since that literally fulfilled the charter's condition of reaching the tidewater, but people in Washington wanted it to end in Washington, connecting to the Tiber Creek and Anacostia river. For that reason, the canal originally opened from Little Falls to Seneca, and the next year, extended down to Georgetown. The Little Falls skirting canal, which was part of the Patowmack Canal, was repurposed for the C & O canal. The Little Falls canal was originally then at a depth of 4 feet, and had to be augmented to the C & O's depth of 6 feet.
The first president of the Canal, Charles F. Mercer, insisted on perfection since this was a work of national importance. This would cost the company more money to build the canal. During his term, he forbade the use of slackwaters for navigation or the use of composite locks (see section below) or reduction of the cross section of the canal prism in difficult terrain. While it was to reduce maintenance costs, later such a policy caused problems due to construction costs being high and difficult to repay. In the end, two slackwaters (Big Slackwater above Dam #4, and Little Slackwater above Dam #5) and composite locks (from Lock 56-88, 69-71) were built anyways.
First part opened
In November 1830, the canal opened from Little Falls to Seneca, not to Georgetown, as people often assume. Later in 1831, the Georgetown section was opened.
In March 1837, there were three surveys made for a possible link to the northeast to Baltimore: via Westminister, via Monocacy-Ligamore, and via Seneca, but they were all were deemed impractical due to lack of water at the summit level.
The canal company began importing indentured labourers in August, 1829. While being promised meat 3 times a day, vegetables, and a "reasonable allowance of whiskey", $8 to $12 per day, $20 for masons, the labourers were quite dissatisfied with the slave-like conditions upon arriving in Alexandria and Georgetown. The main labour force was Irish and German, and due to friction between these groups, they had to be kept in different crews.
In 1832, trying to improve the speed at which the labour force worked, the canal company tried prohibiting liquor, but like Prohibition in the 20's, the company had to repeal it. In August 1832, a cholera epidemic arrived, killing many, and stopping work.
Dispute for Point of Rocks and Second part opened
The narrow strip of available land along the Potomac River from Point of Rocks to Harpers Ferry caused a legal battle between the C & O Canal and the Baltimore and Ohio Railroad (B&O) in 1828 as both sought to exclude the other from its use. Following a Maryland state court battle involving Daniel Webster and Roger B. Taney, the companies later compromised to allow the sharing of the right of way. Afterwards, the section to Harper's ferry was opened in 1834.
The canal initially connected to the Potomac River on the east side of Georgetown by joining Rock Creek east of Lock 1, 0.3 miles (0.5 km) upstream of the Tidewater Lock, whose remnants still exist to the west of the mouth of the creek. In 1831, the first section opened from Georgetown to Seneca, Maryland. By 1833, the canal opened to Harpers Ferry, and at the Georgetown end it was extended 1.5 miles (2.4 km) eastward to Tiber Creek, near the western terminus of the Washington City Canal which extended into the future National Mall and the foot of the United States Capitol. A lock keeper's house at the eastern end of this "Washington Branch" of the C&O Canal remains at the southwest corner of Constitution Avenue and 17th Street, N.W., at the edge of the National Mall in Washington, D.C.
The canal reached Williamsport in 1854.
In 1836, the canal was used as a Star Route for the carriage of mails from Georgetown to Shepherdstown using canal packets. The contract was held by Albert Humrickhouse at $1,000 per annum for a daily service of 72 book miles. The canal approached Hancock, Maryland, by 1839. In 1843, the Potomac Aqueduct Bridge was constructed near the present-day Francis Scott Key Bridge to connect the Chesapeake and Ohio Canal to the Alexandria Canal which led to Alexandria, Virginia.
The Canal reached Dam #6 (west of Hancock, MD) in 1839.
Last 50 Miles
Building the last 50 miles was a major obstacle. Although the final locks (70-75) had been completed earlier than 1842, all but an 18 1/2 mile segment had been done, including the Paw Paw tunnel, the deep cut at Oldtown, and 17 locks. Since it was difficult to obtain stone for the locks, composite locks, sometimes made with kyanized wood  were made.
The engineers, near Paw Paw, had no good solutions. If they followed the river, they would have to cross over to West Virginia to avoid the cliffs, and an agreement with the B&O railroad was that the canal would avoid the south side of the river, unless it was a place where the railroad would not need it. It was later decided to build a tunnel thorough that mountain. Unfortunately, the cost was grossly underestimated.
Originally the company intended to go around Cumberland, behind the town of Wills Creek, but complaints from the citizens and the city caused the board to change their plans, and then went into center of Cumberland. The canal was opened for trade to Cumberland on Thursday, October 10, 1850. On the first day, five canal boats, Southampton, Elizabeth, Ohio, Delaware and Freeman Rawdon loaded with a total of 491 coal, came down from Cumberland. In one day, the C&O carried more coal in the first day of business than the Lehigh Canal for their full year of business in 1820.
By the time the canal reached Cumberland in 1850, the B&O Railroad had reached Cumberland eight years previously. Debt-ridden, the company dropped its plan to continue construction of the next 180 miles (290 km) of the canal into the Ohio Valley. The company long realized (especially with the experience at the Paw Paw tunnel) that construction over the mountains going to Pittsburgh was "wildly unrealistic".
The canal had deteriorated significantly during the Civil War, and needed much repair and maintenance. In 1869 the report to the board stated: During the last ten years little or nothing had been done toward repairing and improving lock-houses, culverts, aqueducts, locks, lock-gates and waste weirs of the Company; many of them had become entirely unfit for use and were becoming worthless, rendering it absolutely essential to the requirements of the Company to have them repaired. Nevertheless, much improvement had been done in the years after the war, for instance, replacing dams #4 and #5 by the end of the decade.
The canal company did have a few good years and they managed to pay back some of their bonds. The early 1870s, which Unrau calls the "Golden Years" were particularly good. Yet there were still problems, besides flood damage. By 1872, problems with vessels unfit for navigation became so bad, the company put together a committee to inspect and re-register vessels every year. One example in July 1876 was the leaky Lezan Ragan which was leaking badly when loaded in Cumberland, yet the crew kept her floating by pumping. She hit some abutments of the locks near Great Falls, and finally sank at the opening Lock 15 (at the head of Widewater).
The company also installed a telephone system in the 1870s to aid in communication and coordination (see below for more information and references).
For a brief period in the 1860s and 1870's, the company attempted to prevent boating on Sundays, but due to boatmen breaking padlocks on the lock gates and violent confrontations, the company gave up trying to enforce the rule 
While a trip from Cumberland to Georgetown was about 7 days, there were several speed records set, from boat races. The fastest known time from Georgetown to Cumberland for a light boat was 62 hours, set by Raleigh Bender from Sharpsburg. Dent Shupp made it from Cumberland to Williamsport in 35 hours with 128 tons of coal.
The disastrous flood of 1889, the canal company went into receivership, whereupon the Baltimore and Ohio railroad gained ownership of the canal, primarily to keep the right of way from falling into the hands of the rival Western Maryland railroad.
This, of course, caused major changes in canal business. In efforts to streamline the business especially after 1902, operations shifted away from independent boatmen owning their own boats, to company owned boats. From boats which had colorful names, with private owners, they became numbered boats, run under a schedule. During the waning years, the boats had the name "Canal Towage Company" with a number, instead of individual names such as Bertha M. Young or Lezen Ragan.
Flood of 1924
The flood of 1924 caused major damage to the canal. Most of the railroad and canal bridges near Hancock were destroyed, opened a breach in Dam #1, and much damage to the banks and masonry of the canal. Although the railroad did some maintenance ostensibly that the canal could quickly be restored to operation, mainly the Georgetown level (Dam #1 and below) was fixed to supply Georgetown's mills with water for operation. There was no boating season in 1924, and navigation ceased. Unfortunately, some communities such as Glen Echo and Cumberland already used the canal to dump sewage, and G.L. Nicholson called the canal a "public nuisance" due to the sewage and being a breeding ground for mosquitoes 
Flood of 1936
This flood caused even more damage to abandoned canal, destroying lockhouses, levels, and other structures. There were some efforts at restoration, mainly to the Georgetown level so that the factories could have their water supply. Due to inattention of the B&O railroad, the canal became a "magnificent wreck".
Tolls and revenue
Tolls were charged for cargo on the canal. In 1851, for instance, the toll rates on the Canal were set as follows:
|Item||Per ton per mile, For first 20 miles||Per ton per mile thereafter|
|Coal||¼ cent||¼ cent|
|Slaughtered hogs, bacon & meat||2 cents||1 cent|
|Whiskey and spirits, fish fresh & salted||2 cents||1 cent|
|Salt||1 cent||¾ cent|
|Fire brick||1 cent||½ cent|
|Bricks, ice||1 cent||¼ cent|
|Sand, gravel, clay, earth, paving stones||¼ cent||¼ cent|
Tolls varied greatly, and frequently the board adopted new toll rates.
Of course, wily boatmen tried to ship extra things in the boats, not listed on the waybills, to avoid paying tolls. For instance, in 1873, one boat went from Georgetown to Harpers Ferry with 225 hidden sacks of salt, before the company found out
The items transported on the canal varied. In the early days, before completion for instance in 1845, the shipments were as follows:
|Item sent downstream||Quantity||Items sent upstream||Quantity|
|Flour||170,464 barrels||Salted Fish||4,569 barrels|
|Wheat||299,607 bushels||Salt||1,265 tons|
|Corn||126,799 bushels||Plaster||4,721 tons|
|Oats||35,464 bushels||Lumber||820,000 feet, board measure|
|Mill Offal||38,575 bushels||Potatoes||2,511 bushels|
|Corn Meal||16,327 bushels||Bricks||118,225 units|
|Pork||15,250 pounds||Wheat||1,708 bushels|
|Lumber||508,083 feet, board measure||Oysters||1,351 bushels|
Business after 1891
After 1891, the canal principally transported coal, and sometimes West Virginia limestone, wood, lumber, sand, and flour, but statistics were only kept for coal  In the last few years, the tonnage and tolls for coal were as follows
Boatmen came down to lock 5, called "Willard's lock" or "Waybill Lock", whereupon the locktender would sign the waybill, and report it to the office. If they did not get orders at that lock, they waited near the aqueduct bridge in Georgetown, until orders came through. A tugboat on the river would pull the boats to other points, e.g. Navy Yard, Indianhead, Alexandria.
|Year||Coal Tonnage||Tolls collected|
Business after 1924
After the flood damage of 1924, the railroad only fixed the part of the canal serving Georgetown, since they sold water to the mills therein, leaving the rest of the canal in disrepair. In 1928-1929 there was some talk of restoring and reopening the canal from Cumberland to Williamsport, but with the onset of the Great Depression, the plans were never realized
The company levied fines for infractions, such as traveling without a waybill or destruction of canal property such as lock gates or canal masonry. For instance:
- May 30, 1877, Capt. Thomas Fisher fined $10 (about $423 USD in 2012) for passing through lock without waybill
- Oct 22, 1877, R. Cropley's scow, fined $25 for knocking out gate in Lock No. 5 [Brookmont Lock]
- Nov. 12, 1877, Capt. Joseph Little, fined $10 for running into crib at Lock No. 9 [Seven Locks]
- July 4, 1878, Boat John Sherman, fined $62.70 for unloading and raising (note: this was on Independence Day)
- Aug 30, 1878, Steamer Scrivenes, fined $50, Allowing the Bertha M. Young in tow to sink on Level 36 and abandoning her at night without giving notice, causing navigation to be suspended 36 hrs.
- May 5, 1879, Capt. Jacob Hooker fined $40, Running into and breaking gate at Lock No. 40
- Jan 14, 1880, Boat Harry & Ralph, fined $5, Running into gate at Darbey’s Lock (Note: this was in winter, when the canal was usually drained for repairs. One wonders what these guys were doing)
- Jun 12, 1880, G.L. Booth, find $4.40, for pumping.
In 1938, the abandoned canal was obtained from the B&O by the United States in exchange for a loan from the federal Reconstruction Finance Corporation. The government planned to restore it as a recreation area. By 1940, the first 22 miles (35 km) of the canal were repaired and rewatered, from Georgetown to Violettes lock and returned to operating condition. The first Canal Clipper boat, giving mule driven rides, began in 1941. It was later replaced by the John Quincy Adams in the 1960s.
The project was halted when the United States entered World War II and resources were needed elsewhere. In 1942, freshets destroyed the rewatered sections of the canal. Yet Arthur E. Demeray pressed that the canal from Dam #1 be restored, to supply water to the Dalecarlia Reservoir in case sabotage or bombing destroyed the normal conduits of water. Since this transformed the canal into a concern of national security, in 1942, the War Production Board approved the work. By 1943, Congress had funded the work, repairs were done, and the National Park Service resumed boat trips in October 1943.
After the war, Congress expressed interest in developing the canal and towpath as a parkway. Because of the flooding from the 1920s to the 1940s, the Army Corps of Engineers proposed buildign 14 dams, that would have permanently inundated 74 miles of towpath, as well as the Monocacy and Antietam aqueducts. Around 1945, the Corps wanted to remove Dam #8, which would destroy any hope of rewatering the canal above Dam #5, as well as put a levee around in the Cumberland area. Much of this was done, with the NPS cooperating with the Corps, since maintaining an operating canal all the way to Cumberland was too expensive, as well as wanting to preserve the western parts of the canal.
The idea of turning the canal over to automobiles was opposed by some, including United States Supreme Court Associate Justice William O. Douglas. In March 1954, Douglas led an eight-day hike of the towpath from Cumberland to D.C. Although 58 people participated in one part of the hike or another, only nine men, including Douglas, hiked the full 184.5 miles (297 km). Popular response to and press coverage of the hike turned the tide against the parkway idea and, on January 8, 1971, the canal was designated a National Historical Park.
Presently the park includes nearly 20,000 acres (80 km²) and receives over 3 million recorded visits each year. Flooding continues to threaten historical structures on the canal and attempts at restoration. The Park Service has re-watered portions of the canal, but the majority of the canal does not have water in it.
Today the park is a popular getaway for Washington residents. The towpath is popular with bikers and joggers. Fishing and boating are popular in the re-watered portions, and whitewater kayakers tackling the world class rapids of the Potomac sometimes use the canal to shuttle upstream. The park offers rides on two reproduction canal boats, the Georgetown and the Charles F. Mercer, (named after the first president of the Canal corporation, and note: this is not the first boat on the canal named Charles F. Mercer.) during the spring, summer and autumn. The boats are pulled by mules, and park rangers in historical dress work the locks and boat while presenting a historical program.
Locks and engineering
Lift Locks and Guard Locks
To build the canal, the C&O Canal Company utilized a total of 74 lift locks that raised the canal from sea level at Georgetown to 610 feet (190 m) at Cumberland. Eleven stone aqueducts were built to carry the canal over the Potomac's tributaries. In addition, seven dams were built to supply water to the canal, waste weirs to control water flow, and 200 culverts to carry roads and streams underneath the canal. An assortment of lockhouses, bridges, and stop gates were also constructed along the canal's path.
Locks 8-27 and their accompanying lock houses were made from Seneca red sandstone, quarried from the Seneca Quarry, as was Aqueduct No. 1, better known as Seneca Aqueduct. This unique structure is the only aqueduct made from Seneca red sandstone and is doubly unique for being the only aqueduct on the C&O that is also a lock (Lock 24, Riley's Lock).
Seven guard locks, often called inlet locks (numbered 1 through 8) were built to allow water and sometimes boats (particularly at Big Slackwater and Little Slackwater) to enter. Dam #7 and Guard Lock #7 were proposed (near mile 164 at the South Branch of the Potomac) but never built. In 1856, there was a steam pump put at that site. Later, in 1872, a new steam pump was put near mile 174.
Three additional river locks were built, to allow boats to enter the canal at the river, as demanded by the Virginia legislature for buying canal stock. They were at Goose Creek (below Edwards Ferry, Lock 25), near the Shenendoah River just below Lock 33, and at Shepherdstown.
The Goose Creek locks were to allow boats from the Goose Creek and Little River Navigation Company to enter. Only one Goose Creek boat was documented to enter the C&O canal, and there is no documentation of a C&O boat entering Goose Creek. The lock was eventually converted into a waste weir.
The Shenandoah river (about 422 feet below Lock 33) lock let boats cross to Harpers Ferry with the mules walking on the railroad bridge, up the Shenandoah river, to the old Potomac Canal Bypass on the Shenandoah river by Virginius island. The railroad refused to let mules walk on the bridge, and from lack of business, the lock was abandoned. Stones from that lock were used for other purposes.
After the 1889 flood destroyed the nearby dam in Shepherdstown, the raison d'être for the Shepherdstown lock was gone, and so it was filled in.
At night, locktenders were required to remove the cranks and handles from all paddle valves to prevent unauthorized use.
Despite Charles F. Mercer not wanting any composite locks, due to measures to economize on the last 50 miles of construction, and the scarcity of good building stone, locks 58-71 are composite locks. That means, the lock masonry is built of rubble and inferior undressed stone. Since that makes a rough surface which damages the boats, the locks were originally lined with wood to protect the boats. This wood sheathing had to be replaced. In time, some of the composite locks were lined with concrete, since the wood kept rotting.
There were three streams used as feeders: Rocky Run feeder (section #9, around 7 Locks), Great Falls feeder (section #18) and the Tuscarora feeder (section #78). There was a contemplated feeder at the Monocacy (not built)., as well as other places. Of course, the remains of the Potomac Company Little Falls skirting canal was used as a feeder also.
The remains of the Tuscarora feeder can still be seen, but it was made redundant by Dam #3 and was no longer used.
Despite Charles F. Mercer, two slackwaters were used for navigation: Big Slackwater at Dam #4, and Little Slackwater at Dam #5. Big Slackwater is about 3 miles long, Little Slackwater is about 1/2 mile long. The boats had to navigate despite winds, currents, and debris in the channel. In February 1837, the board of directors discussed using steam power in the slackwater for the boats, but instead decided on a permanent towpath. The towpath for Big Slackwater was completed in 1838 for $31,416.36, and the towpath for Little Slackwater was completed in 1839 for $8,204.40.
Little Slackwater was a tricky place to navegate. Not only did it have a lot of hairpin turns, but also just before Guard lock #5, there was a strip of land in the water called "the pier" [which exists even today]: loaded boats going downstream would have to go outside the pier, and unloaded boats on the inside, thus making steering difficult for the loaded boats to get into the lock. If the current was fast in the river it could go as fast as the boat, rendering the tiller useless, and thus, a boat could be almost impossible to steer. One time a towrope broke, and the boat went over Dam #5, causing loss of life.
Boatmen reported that it was easier to navigate in the slackwaters than the aqueducts, since there was room for the water to move around the boat. Places like aqueducts, where there was little room for the water to move, were difficult for the mules to pull the boat through.
Waste weirs, spillways, and informal overflows (mule drinks)
To regulate the level of water in the canal prism, waste weirs, informal overflows, and spillways were used.
Waste weirs removed the surges of water from storms or excess when a lock was emptied. Boards could be removed or added to adjust the amount of water in the level. If one had to empty the whole level for winter, repairs, or emergencies, waste weirs often had paddle valves (similar to those found in locks) at the bottom which could be opened to let the water out.
Waste weirs come in several styles. Originally they were made of concrete masonry with boards on top making a bridge with mules to pass over. A possible example of an old-style waste weir (abandoned) is at 39.49 miles, above Lock 26 (Wood's Lock). Most of these old waste weirs were replaced with concrete structures in 1906. Another used to be at Pennyfield lock in 1909-1911.
Spillways are made of concrete, and can be on either side, but if on the towpath side, have a bridge so people (and mules) can cross without getting the feet wet. High water simply flows over the spillway and out of the canal. The longest spillway, near Chain Bridge, is 354 feet long, was made in 1830 (but has been worked on since). Another spillway near Foxhall road at mile 1.51, was made in 1835. The spillway and waste weir at Big Pool was built in the 1840s 
An informal overflow or mule drink was a dip in the towpath allowing water to flow over, similar to a spillway, but without the bridge or the concrete construction (hence, were more informal). The canalers called these "mule drinks". There are documented informal overflows at mileage 10.76 (shown in the photograph), 49.70, and 58.08. These usually had a drainage ditch which was riprapped with stone to prevent erosion. Historically the towpath dropped two feet to form this overflow. Due to silting, construction, etc. many of these overflows are now difficult to find. Hahn states that clues to finding these overflows include: a gully without a culvert, a sudden lowering of the towpath, or the signs of riprap on the towpath or the gully itself. Many of these (e.g. the one at Pennyfield lock) were replaced by a waste weir.
Paw Paw tunnel
One of the most impressive engineering features of the canal is the Paw Paw Tunnel, which runs for 3,118 feet (950 m) under a mountain. Built to save six miles (10 km) of construction around the obstacle, the 3/4-mile tunnel used over six million bricks. The tunnel took almost twelve years to build; in the end, the tunnel was only wide enough for single lane traffic. One notorious incident included two captains who refused to budge for several days. The company official threw green cornstalks onto a roaring fire at the upwind portion of the tunnel, smoking the offenders out.
Starting in 1875, a canal inclined plane was built two miles (3 km) upriver from Georgetown, so that boats whose destination was downriver from Washington could bypass the congestion (and price gouging of independent wharf owners) in Georgetown. Originally the company planned to build a river lock, but then discovered that such a lock occasionally would consume more water than the level could provide. They then planned to make an inclined plane, much like the Morris Canal. The inclined plane was dismantled after a major flood in 1889 when ownership of the canal transferred to the B&O Railroad, which operated the canal to prevent its right of way (particularly at Point of Rocks) from falling into the hands of the Western Maryland Railway.
In the late 1870s, the Company installed a telephone system, rather than a telegraph as was the railroad practice, for $15,000. Completed in October 1879, it had 43 stations along the canal. It was divided into sections with three switches, placed respectively at Dam #4, Dam #6, and Wood's Lock (head of 9 Mile level, i.e. Lock 26). It is unknown if there are currently any remains of this system.
To carry small streams under the canal, small culverts, usually of masonry, were built. For instance, culvert #30 was built in 1835 to carry Muddy Branch under the canal. Unfortunately culverts are prone to collapse due to tree roots growing into the canal prism; in addition, rubbish from floods plug culverts, causing floods and more damage. Some culverts have disappeared or were abandoned, although they still appear in company records.
Eleven aqueducts carried the canal over rivers and large streams, where they were too large for a culvert.
Boats on the Canal
The following classifications of boats originally defined for the canal were as follows:
- Packet Boats, for passengers
- Freight boats
- Scows, especially work scows for construction and maintenance, as well as ice breaking
Classifications were to change. In 1851, the classes were A, B, C, D, E, and F, depending on dimensions and tonnage 
During the declining years, freight boats were generally made in Cumberland.
Boats were to keep to the right. Certain craft had preference over others: "boats had the right of way over rafts, descending boats over ascending craft, packets over freight boats at all times, and packets carrying the mail over all others", and later, repair boats actively involved in repair had preference over everybody else.
It was forbidden to moor boats, rafts, or anything on the towpath side of the canal(which would, of course, impede any traffic at night). For that reason, boats would tie up on the berm side for the night.
Boats carried oakum and chisels to patch leaks. There were also boat repair areas, for instance, beside Lock 35 and at Lock 47 (Four Locks), to repair boats. The boat would settle on raised beams (at lock 35, they were made of concrete), as the drydock was drained, and the men could make the necessary repairs,  using tin and tar. Originally, the canal plans did not have provisions for drydocks or repairs of boats, but by 1838 there were frequent complaints about drifting rafts and wrecks obstructing navigation. The company made provisions for drydocks to get rid of these undesirable craft from the canal  In the mid 1800's the Canal Company authorized at least 6 drydocks, documented at the following locations: Locks 45-46, Lock 47 (Four Locks), Lock 44 (Shepherdstown), Above Lock 14 (near Carderock), Edwards Ferry (Lock 25), and in the rear of Lock 10 (Seven Locks).
Icebreakers were used on the canal, for instance, at the end of the boating season when winter froze the canal, so that the last group of boats could go home. The icebreaker was typically a company scow filled with pig iron. Mules would pull the boat onto the ice, and the weight would break the ice. During the Civil war, the canal company attempted to keep the canal open during the winters of 1861-1862, despite the fact that winters were usually for repairs. Icebreaker boats were used to keep the channel free of ice, so that the military could move supplies.
Most boats were drawn by mules. Mules lasted about 15 years. Mules were often changed at locks, over gangplanks. Some boatmen would change teams by making the mules swim to the shore to change teams, leading to mules drowning as a result. Mules were bought, at 2½ years, often from Kentucky, and were broken in by having them drag logs.
Getting a boat fully loaded boat moving was not easy for the mules, and overdriving them, especially at the basin in Cumberland where there was no water current to help them move the boat, was common, resulting in many spavined mules. To get a loaded boat going, the mules would have to walk until the line was taut, then put their weight into it, and step once the boat had moved, and repeat this process. Within 25 feet, the boat would be moving.
Mules were harnessed, one behind the other, slantwise, which (for some reason) pulled the boat straighter, than if they were abreast.
Dogs were useful to a boat captain on the canal to drive mules and also to swim to take the towline to hitch the mules.
Horses were occasionally used to pull boats, but they did not last as long as mules.
Steamboats on the Canal
There were occasionally steam boats, one being authorized in 1824  In 1850, the N S Denny company operated some steam driven tugboats on the Canal. The board of directors discussed having steamboats for Big Slackwater, but that was abandoned in favor of a towpath along the side.
The canal hired level walkers to walk the level with a shovel, looking for leaks, and repairing them. Large leaks were reported to the division superintendent, who would send out a crew with a repair scow.
Boatmen said that crabs caused leaks, as did muskrats. The Company gave a 25 cent bounty on each muskrat.
Points of interest
- East of Mile 000: Lock Keeper's House at eastern end of Washington Branch of C&O Canal.
- Mile 000: Tidewater Lock
- Mile 000: Rock Creek Park
- Mile 000: C&O Canal Monument
- Mile 000: Lock 1
- Mile 000: Georgetown, Washington, D.C. Coordinates: and Georgetown Visitor Center
- Mile 000: Potomac Heritage Trail - on Virginia side of river. (Bikes can use it below Francis Scott Key Bridge.)
- Mile 001: Abutment and former canal bed of Potomac Aqueduct Bridge
- Mile 001: Capital Crescent Trail
- Mile 002: Inclined Plane
- Mile 005.4: Lock 6 where C&O groundbreaking took place on July 4, 1828
- Mile 007: Glen Echo Park (Maryland) and Lock 7
- Mile 008.4: Lock 8, the first of the "Seven Locks" and the Potomac Conservancy's River Center
- Mile 014: Billy Goat Trail at Great Falls, Great Falls Tavern
- Mile 016: Swain's Lock at Lock 21, Potomac, Md
- Mile 020: Pennyfield Lock
- Mile 022: Violette’s Lock (Lock 23) The canal has water in it from here south.
- Mile 022.7: Seneca Aqueduct/Riley's Lock
- Mile 023: Seneca Quarry
- Mile 026: Dierssen Wildlife Management Area & McKee-Beshers Wildlife Management Area
- Mile 035: Poolesville, Maryland
- Mile 035: White's Ferry
- Mile 042: Monocacy Aqueduct
- Mile 044.6: Noland's Ferry
- Mile 048: Point of Rocks, Maryland
- Mile 055: Brunswick, Maryland
- Mile 058: Appalachian Trail
- Mile 060: Harpers Ferry, West Virginia
- Mile 069.4: Antietam Creek Aqueduct
- Mile 073: Ferry Hill, Maryland
- Mile 073: Shepherdstown, West Virginia
- Mile 073: Sharpsburg, Maryland
- Mile 099: Williamsport, Maryland
- Mile 107: Dam No. 5
- Mile 110: Four Locks - Once a thriving community of homes and businesses supporting the canal.
- Mile 110.4: McCoy's Ferry - Campground and historic American Civil War crossing
- Mile 112: Fort Frederick State Park; Western Maryland Rail Trail begins
- Mile 124: Hancock, Maryland
- Mile 124: Rt. 522 Bridge to Berkeley Springs, West Virginia; Western Maryland Rail Trail diverges
- Mile 140: Little Orleans, Maryland
- Mile 151: Paw Paw Tunnel - The path into the tunnel from the east been reopened in May 2013.
- Mile 151: Paw Paw, West Virginia
- Mile 165: Oldtown, Maryland
- Mile 184: Cumberland, Maryland
- Mile 184: Canal Place
- Mile 184: Western Maryland Scenic Railroad
||Constructs such as ibid., loc. cit. and idem are discouraged by Wikipedia's style guide for footnotes, as they are easily broken. Please improve this article by replacing them with named references (quick guide), or an abbreviated title. (June 2013)|
- "The Grand Old Ditch: the C&O In American Transportation History "
- Hahn, 1.
- Kytle P.10
- Kytle, P. 12
- Kytle, Elizabeth. Home on the Canal. Seven Locks Press, 1983, ISBN 0-932929-13-5 p. 20
- Kytle p. 25
- Bearss, Edwin C, The Composite Locks, NPS, 1968, p. 57
- Kytle p. 27
- Harland D. Unrau. "Historical Resource Study: Chesapeake & Ohio Canal". [US Department of the Interior, National Park Service]. Retrieved 2013-05-02. p. 25
- Kytle, P. 84
- Unrau P. 41
- Kytle P. 33-34
- Kytle P. 43
- Lynch, John A. "Justice Douglas, the Chesapeake & Ohio Canal, and Maryland Legal History". University of Baltimore Law Forum 35 (Spring 2005): 104–125
- Kytle p. 84
- Coordinates of Lock 1:
- Coordinates of tidewater lock:
- Hahn, 6.
- ""The Canal Connection" marker". HMdb.org: The Historical Marker Database. Retrieved 2011-03-02.
- "Washington City Canal: Plaque beside the Lockkeeper's House marking the former location of in Washington, D.C.". dcMemorials.com: Memorials, monuments, statues & other outdoor art in the Washington D.C. area & beyond, by M. Solberg. Retrieved 2011-03-02.
- ""The Washington City Canal" marker". HMdb.org: The Historical Marker Database. Retrieved 2011-03-02.
- ""Lock Keeper’s House" marker". HMdb.org: The Historical Marker Database. Retrieved 2011-03-02.
- Coordinates of lock keeper's house:
- Kytle, p. 84
- Coordinates of abutment and canal bed of Potomac Aqueduct Bridge:
- Edwin C. Bearss. "The Composite Locks". [US Department of the Interior, National Park Service]. Retrieved 2013-05-24. p.20
- Bearss p. 33
- Kytle p. 53-54
- Unrau P.207, 208
- Bearss P. 57
- Kytle P. 64
- Mackintosh, 1.
- Hahn, 7.
- Kytle p. 61, note #10
- 41st annual report of the C&O Canal Company (1869), p. 4-5
- Unrau p. 476
- Unrau P. 813
- Unrau p. 813
- Unrau p. 811
- Unrau p. 814-815
- Unrau p. 318
- Donald R. Shaffer. "We are Again in the Midst of Trouble: Flooding on the Potomac River and the Struggle for the Sustainability of the Chesapeake and Ohio Canal, 1828-1996". [US Department of the Interior, National Park Service]. Retrieved 2013-05-23. P. 64
- Unrau p. 321
- Shaffer p. 65
- Unrau P. 457.
- Unrau P. 814
- Unrau, P.446-447
- Unrau P. 498
- Kytle, 154-155
- Unrau P. 499
- Unrau p. 848
- Shaffer P. 71
- Shaffer P. 73
- Shaffer p. 76
- Shaffer p. 78
- Shaffer P. 79
- Peck, Garrett (2012). The Potomac River: A History and Guide. Charleston, SC: The History Press. pp. 62–63. ISBN 978-1-60949-600-5.
- Unrau p. 208 footnote, 470
- Hahn, Towpath Guide, P. 62-63
- Hahn, Towapath Guide, P. 99-100
- Unrau p. 167, 238
- Unrau P. 336
- Kytle,P. 71-72.
- Unrau p. 185
- Hahn, Towpath Guide, P. 82.
- Unrau P. 343
- Unrau P. 251-252
- Kytle 145-146
- Kytle, p.66
- Kytle p.67
- Hahn, Towpath Guide, P. 75
- Kytle P. 271
- Hahn, Towpath Guide, P. 36, 86, 96
- Hahn Towpath Guide, P. 96
- Hahn, Towpath Guide, p. 86
- http://www.canaltrust.org/quarters/pdf/Pennyfield_Lock_CLI.pdf P. 93
- National Park Service, "The Paw Paw Tunnel is 3118 feet (950 m) long and is lined with over six million bricks. The 3/4 mile long tunnel saved the canal builders almost six miles (10 km) of construction along the Paw Paw bends of the Potomac River. It took twelve years to build and was only wide enough for single lane traffic."
- Coordinates of inclined plane:
- Unrau P. 480
- Unrau, P. 578
- Unrau, P. 594
- Shaffer p. 83
- Hahn, Towpath Guide, p. 97, for instance
- Unrau p. 239-241
- Unrau, P. 338
- Unrau p. 761
- Unrau P. 337
- Unrau P. 349-350
- Unrau p. 357
- Unrau P. 365
- Unrau P. 367
- Unrau P. 383
- Kytle p. 221
- Hahn, Towpath Guide, p. 112
- Unrau P. 337.
- Unrau P. 360-361
- Unrau P. 820
- Unrau P. 724
- Unrau P. 219-220
- Kytle P. 173
- Kytle p. 155
- Kytle p. 171 Footnote
- Unrau P. 220
- Unrau, p. 344
- Unrau, P. 345
- C&O Canal official NPS web page. "Park Alerts In Effect". National Park Service. Retrieved 2 May 2013.
Mackintosh, Barry (1991). C&O Canal: The Making of A Park. Washington, D.C.: National Park Service, Department of the Interior.
- Life on the Chesapeake & Ohio Canal, 1859 [York, Pa. : American Canal and Transportation Center, 1975]
- Achenbach, Joel. The Grand Idea: George Washington's Potomac and the Race to the West, Simon and Schuster, 2004.
- Blackford, John, 1771-1839. Ferry Hill Plantation journal: life on the Potomac River and the Chesapeake and Ohio Canal, 4 January 1838-15 January 1839 2d ed. Shepherdstown, W. Va. : [American Canal and Transportation Center], 1975.
- Cotton, Robert. The Chesapeake and Ohio Canal Through the Lens of Sir Robert Cotton
- Fradin, Morris. Hey-ey-ey, lock! Cabin John, Md., See-and-Know Press, 1974
- Gutheim, Frederick. The Potomac. New York: Rinehart and Co., 1949.
- Guzy, Dan. Navigation on the Upper Potomac and Its Tributaries. Western Maryland Regional Library, 2011
- Hahn, Thomas F. The Chesapeake and Ohio Canal Lock-Houses and Lock-Keepers.
- Hahn, Thomas F. Towpath Guide to the C&O Canal: Georgetown Tidelock to Cumberland. Shepherdstown, WV: American Canal and Transportation Center, 1985.
- High, Mike. The C&O Canal Companion, Johns Hopkins University Press, 2001.
- Kapsch, Robert and Kapsch, Elizabeth Perry. Monocacy Aqueduct on the Chesapeake and Ohio Canal. Medley Press, 2005.
- Kapsch, Robert. The Potomac Canal, George Washington and the Waterway West.Morgantown, WV: West Virginia University Press, 2007.
- Kytle, Elizabeth. Home on the Canal, Cabin John, Md.: Seven Locks Press, c. 1983.
- Martin, Edwin. A Beginner's Guide to Wildflowers of the C and O Towpath, 1984.
- Mulligan, Kate. Canal Parks, Museums and Characters of the Mid-Atlantic, Wakefield Press, Washington, DC, 1999.
- Mulligan, Kate. Towns along the Towpath, 1997. (Available from C &O Association) Here is Chapter 3 about Seneca.
- National Park Service, Chesapeake and Ohio Canal National Historical Park Washington, DC: NPS Division of Publications, 1991.
- Rada, James Jr. Canawlers, Legacy Press, 2001.
- Southworth, Scott, et al. Geology of the Chesapeake and Ohio Canal National Historical Park and Potomac River Corridor, District of Columbia, Maryland, West Virginia, and Virginia: U.S. Geological Survey Professional Paper 1691, 2008.
||This article's use of external links may not follow Wikipedia's policies or guidelines. (January 2013)|
|Wikimedia Commons has media related to: Chesapeake & Ohio Canal National Historical Park|
- Official National Park Service Site
- The Building of the Chesapeake and Ohio Canal, a National Park Service Teaching with Historic Places (TwHP) lesson plan
- Jack Rottier photographs and papers of the C and O Canal Online Collection, Special Collections Research Center, Estelle and Melvin Gelman Library, The George Washington University.
- Everything About The C&O Canal
- The Chesapeake and Ohio Canal
- C&O Canal Bicycling Guide
- A Virtual Tour of the C&O Canal
- Another Virtual Tour of the C&O Canal
- C&O Canal Association
- The economic impact of the C&O Canal on canal communities in Washington County, Maryland
- Thomas Hahn Chesapeake and Ohio Canal Collection Finding Aid, Special Collections Research Center, Estelle and Melvin Gelman Library, The George Washington University
- The Chesapeake and Ohio Canal Documentary produced by WETA-TV