Allegheny City (1788–1907) was a Pennsylvania municipality located on the north side of the junction of the Allegheny and Ohio rivers, across from downtown Pittsburgh. It was annexed by Pittsburgh in 1907. The area today is known as the North Side of Pittsburgh, and its waterfront district, along the Allegheny and Ohio Rivers, as the North Shore.
Prior to the 1850s, this area was largely farmland, but was subdivided into residential lots, first for the growing German population and later for the Croats. It was commonly referred to as "Deutschtown".
A massive urban redevelopment project in the 1960s demolished the core of historic Allegheny City, leaving only the Commons of Allegheny Center and its surrounding neighborhoods to evoke the area's past. The Carnegie Library, the Old Post Office Building, and the Buhl Planetarium buildings were not demolished. Major portions of the neighborhoods of Allegheny West, Manchester, Central Northside, California-Kirkbride (Old Allegheny Rows), and East Allegheny are listed on the National Register of Historic Places, including the Mexican War Streets in Central Northside.
The area of Allegheny City included the present Pittsburgh neighborhoods of Allegheny Center, Allegheny West, Brighton Heights, California-Kirkbride, Central Northside, Chateau, East Allegheny, Fineview, Manchester, Marshall-Shadeland, North Shore, Northview Heights, Perry North, Perry South, Spring Garden, Spring Hill–City View, Summer Hill, and Troy Hill.
The City of Allegheny was laid out in 1788 according to a plan by John Redick. The lots were sold in Philadelphia by the State government or given as payment to Revolutionary War veterans. It was incorporated as a borough in 1828 and as a city in 1840. The population rose to 53,180 in 1870.
Allegheny was an industrial city and had numerous commercial areas, churches, and social organizations, packing houses, tanneries, soap factories and glue factories that provided opportunities for employment to the primarily German immigrants who settled there. The H.J. Heinz Company built its factory in Allegheny City, close to the Chestnut Street bridge, which has been replaced by the 16th Street Bridge. Heyl & Patterson Inc., a manufacturer of railcar dumpers and ship unloaders, also established a factory in Allegheny City. The surviving structures are now occupied by a furniture warehouse and a bus garage.
By the middle of the nineteenth century, the "Made in Allegheny" label could be found not only on basic iron but on rope, plows, cotton cloth, wool, food, paper, paint, steam engines, wagons and carts, meat, soap, candles, lumber, linseed oil, furniture and a host of other diversified products.
Annexation by Pittsburgh
The absorption of Allegheny began in 1906, was effected in 1907, authorized by the U.S. Supreme Court in a landmark decision Hunter v. City of Pittsburgh  in 1907, and finally approved by the United States Government in 1911. The annexation was controversial at the time as an overwhelming majority of Allegheny City residents were opposed to the merger. Previous Pennsylvania law had directed that a majority of the voters in each merging municipality had to approve the agreement. In 1906, a new law was quietly passed by the State Assembly that allowed a majority of the total voters in both combined municipalities to approve the merger. The annexation was rejected by the residents of Allegheny City by a 2:1 margin but was approved by much more populous Pittsburgh and the annexation bill passed into law. Allegheny City residents tried unsuccessfully for years to have the annexation overturned in court.
The population of Pittsburgh rose from 321,616 in 1900 to 533,905 in 1910, which included the 132,283 who lived in Allegheny in 1910 when the last census of Allegheny was taken.
When the two cities were joined, both of the old ward systems were discarded. They were replaced by a new ward system made of 27 wards. In the new ward system, Allegheny became wards 21 to 27, thus its past location is easily determinable by viewing a map that depicts the ward system .
The Teutonia Männerchor Hall in the East Allegheny (Deutschtown) neighborhood of Pittsburgh, Pennsylvania, is a building constructed in 1888. It was listed on the National Register of Historic Places in 2004. The Teutonia Männerchor is a private membership club with the purpose of furthering choral singing, German cultural traditions and good fellowship. The club features a number of heritage activities and celebrations, including choral singing in German and folk dancing.
The Priory is really two historic landmarks - the 1852 St. Mary's German Catholic Church and the adjacent 1888 home for Bavarian Benedictine priests and brothers. Once a largely German parish, the church later merged with nearby Italian and Polish congregations. The church and rectory have since closed, and currently house a banquet hall and a bed-and-breakfast.
Although Penn Brewery only began in 1987, it is housed in the old Eberhardt & Ober Brewery (1882-1906) buildings. Penn Brewery makes the award-winning Penn Pilsner and a number of other specialty beers. The "tied house" (brewery owned restaurant) features a full German menu and live music.
Saint Nicholas Church
Saint Nicholas Croatian Catholic Church, nestled in the hillside near the Allegheny River, is the first Croatian Church in America.
Ridge Avenue Neighborhood
Ridge Avenue, in its heyday between 1890 and 1910, was known as "Millionarie's Row". But after only 20 years, things started turning downhill for Ridge Avenue and its environs. In fact, the entire North Side community was beginning to fray after having been annexed by Pittsburgh in 1907.
Mexican War Streets
In the late 19th century, Allegheny became known for its stately homes, occupied by some of the area's wealthy families. One such area became known as The Mexican War Streets.
The Mexican War Streets were laid out in 1848 by General William Robinson, Jr. who later became mayor of the city of Allegheny. Just returned from service in the Mexican War, he subdivided his land and named the new streets after the battles and generals (Buena Vista Street, Filson Way, Monterey Street, Palo Alto Street, Resaca Place, Sherman Avenue, Taylor Avenue) of that war.
Carnegie Free Public Libraries
Andrew Carnegie constructed one of his Carnegie Free Public Libraries in Allegheny, Pennsylvania.
Allegheny was the location of Exposition Park, the home field of the professional baseball team named the Pittsburgh Pirates (originally called the Pittsburgh Alleghenies and Pittsburgh Innocents). Today, the North Side of Pittsburgh houses PNC Park, home of the Pittsburgh Pirates, and Heinz Field, home of the Pittsburgh Steelers. These facilities replaced Three Rivers Stadium which was the shared home of both teams.
Felix Brunot Mansion
Historians say the Felix Brunot mansion on Stockton Avenue was once a station on the underground railway, where fugitive slaves from the South stopped for food and shelter.
The original Allegheny Observatory was built in 1859 near Perrysville Avenue by prominent Allegheny citizens who formed the Allegheny Telescope Association. The association donated the observatory to the Western University of Pennsylvania (now the University of Pittsburgh) in 1867 after which it was used for astrophysical, solar, and planetary studies. The observatory maintained a successful subscription time service to railroads via telegraph for many years. A new Allegheny Observatory was built between 1900-1912 in today's Riverview Park and remains owned and operated by the University of Pittsburgh for education, astronomical research, and public lectures and tours.
- Mary Cassatt (1844-1926), born in Allegheny City on May 22, 1844, American impressionist painter and printmaker
- Alexander Gilmore Cochran (1846-1928), born in Allegheny City, was a Democratic member of the U.S. House of Representatives from Pennsylvania
- William Henry Conley, (1840-1897), born in Allegheny City, First President of the Zions Watch Tower and Tract Society. Cofounder Jehovah's Witnesses
- Martha Graham (1894-1991), born in Allegheny City on May 11, 1894, American dancer and choreographer
- Kate Harrington (1831-1917), born in Allegheny City September 20, 1831, teacher, writer, and poet
- George Washington Harris, (1814-1869), born in Allegheny City, steamboat captain and noted humorist, including the "Sut Lovingood" stories 
- Elijah Hise, (1802-1867), born in Allegheny City, lawyer, judge, and United States Congressman from Kentucky
- Robinson Jeffers (1887-1963), a poet known for his epic poetry
- John Pitcairn (1841-1916) Scottish-American industrialist who founded PPG Industries; emigrated to Allegheny City at age five
- Art Rooney (1901-1988), founding owner of the Pittsburgh Steelers franchise in the National Football League
- Dan Rooney owner of the Pittsburgh Steelers franchise in the National Football League
- Charles Taze Russell, (1852-1916), born in Allegheny City, Second President of Watch Tower and Tract Society. Cofounder Jehovah's Witnesses
- George E. Smith or "Pittsburgh Phil" (1862-1905), 1870s resident that became a noted gambler and Thoroughbred owner
- Gertrude Stein (1874-1946), born in Allegheny City on February 2, 1874, American avant-garde writer
- Lois Weber (1879-1939), born in Allegheny City, pioneer silent film actor, screenwriter, producer, and director
- Samuel Pierpoint Langley, (1834-1906), aviation pioneer, astrophysicist
- John A. Brashear, (1840-1920), scientific instrument engineer
- Jack McKee, "The North Side Story," in North Side Directory Chamber of Commerce Members 1960-61
- "U.S. Supreme Court HUNTER v. CITY OF PITTSBURGH, 207 U.S. 161 (1907)". Retrieved 2007-12-12.
- Evelyn Sucher, Michael Eversmeyer and Lauren Uhl, "Historic Districts of Pittsburgh: Mexican War Streets: A City's Legacy: The Fabric of Pittsburgh: A Walking Tour,"
- William J. Switala, "Underground Railroad in Pennsylvania"
- Allegheny City Commercial Districts
- Allegheny City Society
- North Side: A Day in Old Allegheny By Frederick P. Mayer in the Pittsburgh Record, June 1930.
- Across the river Carnegie Library of Pittsburgh historical reprint
- June 11th, 2006 article in the Pittsburgh Tribune-Review on the centennial of the annexation of Allegheny City into Pittsburgh
- German Heritage Sites in Pittsburgh and Allegheny City
- The Teutonia Männerchor
- Underground Railroad in Pennsylvania