Conquest of California

Main article: Mexican–American War

Map of Mexico with Alta California, 1847

The California Campaign (1846−47), colloquially the "Conquest of California" or Conquest of Alta California by the United States, was an initial period of the Mexican–American War that took place in the western part of Mexico's Alta California Department, the present-day state of California. The California Campaign was marked by a series of small battles over 1846 and early 1847.

History

Beginnings

When war was declared on 13 May 1846 between the United States and Mexico, it took almost three months for definitive word of Congress' declaration of war to reach the Pacific coast. U.S. consul Thomas O. Larkin, stationed in the pueblo of Monterey, was concerned about the increasing possibility of war and worked to prevent bloodshed between the Americans and the small Mexican military garrison at the Presidio of Monterey, commanded by José Castro.

United State Army Captain John C. Frémont, on a survey expedition of the U. S. Army Corps of Topographical Engineers with about 60 well-armed men, crossed the Sierra Nevada range in December 1845. They had crossed into the Oregon Territory in May 1846, when he received word that war between Mexico and the U.S. was imminent.

A replica of the first "Bear Flag" now at El Presidio de Sonoma (Sonoma Barracks)

Bear Flag Revolt

Main article: Bear Flag Revolt

On 14 June 1846, the "Bear Flag Revolt" occurred when some 30 rebels, mostly American immigrants, staged a revolt in response to government threats of expulsion and seized the small Mexican Sonoma Barracks garrison, in the pueblo of Sonoma north of San Francisco Bay. They formed the California Republic, created the "Bear Flag," and raised it over Sonoma. Eleven days later, troops led by Frémont, who had acted on his own authority, arrived from Sutter's Fort to support the rebels. No government was ever organized, but the Bear Flag Revolt has become part of the state's folklore.

The present day California state flag is based on this original Bear Flag, and continues to display the words "California Republic."

Naval engagements—Alta California ports captured

Prior to the Mexican–American War, preparations for a possible conflict led to the U.S. Pacific Squadron being extensively reinforced until it had roughly half of the ships in the United States Navy. Since it took 120 to over 200 days to sail from Atlantic ports on the east coast, around Cape Horn, to the Pacific ports in the Sandwich Islands (Hawaiian Islands) and the west coast, these movements had to be made well in advance of any possible conflict to be effective. Initially, with no United States ports in the Pacific, the squadron's ships operated out of storeships that provided naval supplies, purchased food and obtained water from local ports of call in the Sandwich Islands and on the Pacific coast. Their orders were, upon determining "beyond a doubt" that war had been declared, to capture the ports and cities of Alta California.

Commodore John Drake Sloat, commander of the Pacific Squadron, on being informed of an outbreak of hostilities between Mexico and the United States, as well as the Bear Flag Revolt in Sonoma, ordered his naval forces to occupy ports in northern Alta California. Sloat's ships then in the Monterey harbor, the USS Savannah, USS Cyane, and USS Levant, in the "Battle of Monterey" captured the Alta Californian capital city of Monterey on 7 July 1846 without firing a shot. Two days later on 9 July, USS Portsmouth, which had been berthed at Sausalito, in the "Battle of Yerba Buena" captured Yerba Buena (present day San Francisco) without firing a shot. On 15 July, Sloat transferred his command to Commodore Robert F. Stockton, a much more aggressive leader. In July, convincing news of a state of war between the U. S. and Mexico had reached Stockton. The 400 to 650 marines and bluejackets (sailors) of Stockton's Pacific Squadron were the largest U. S. ground force in California. The rest of Stockton's men were needed to man his vessels.

To supplement this remaining force, Commodore Stockton ordered Captain John C. Frémont, on the U. S. Army's Corps of Topographical Engineers survey, to secure 100 volunteers (he received 160), in addition to the California Battalion that he had earlier organized. They were to act primarily as occupation forces to free up Stockton's marines and sailors. The California Battalion's core was the approximately 30 army personnel and 30 scouts, guards, ex-fur trappers, Indians, geographers, topographers and cartographers in Frémont's exploration force, which was joined by about 150 Bear Flaggers.

The American marines, sailors, and militia easily took over the cities and ports of northern California; within days they controlled Monterey, San Francisco, Sonoma, Sutter's Fort, New Helvetia, and other small pueblos in northern Alta California. Nearly all were occupied without a shot being fired. Some of the southern pueblos and ports were also rapidly occupied, with almost no bloodshed.

Californios and the war

Prior to the U.S. occupation, the population of Spanish and Mexican people in Alta California was approximately 1500 men and 6500 women and children, who were known as Californios. Many lived in or near the small Pueblo of Los Angeles (present day Los Angeles). Many other Californios lived on the 455 ranchos of Alta California, which contained slightly more than 8,600,000 acres (35,000 km²), nearly all bestowed by the Spanish and then Mexican governors with an average of about 18,900 acres (76 km²) each.

Most of the approximately 800 American and other immigrants (primarily adult males) lived in the northern half of California, approved of breaking from the Mexican government, and gave only token to no resistance to the forces of Stockton and Frémont.

Southern Alta California

Siege of Los Angeles

Main article: Siege of Los Angeles

In Southern California, Mexican General José Castro and Alta California Governor Pío Pico fled the Pueblo of Los Angeles before the arrival of American forces. On 13 August 1846, when Stockton's forces entered Los Angeles to no resistance, the nearly bloodless conquest of California seemed complete. The force of 36 that Stockton left in Los Angeles, however, was too small and, in addition, enforced a tyrannical control of the citizenry. On 29 September in the Siege of Los Angeles, the independent Californios, under José María Flores' leadership, forced the small American garrison to retire to the harbor.

Soon afterward, 200 reinforcements sent by Stockton and led by U.S. Navy Captain William Mervine, were repulsed in the one-hour Battle of Dominguez Rancho on Rancho San Pedro, on 8 October with four Americans killed. In late November, General Kearny, with a squadron of 100 dragoons, finally reached the Colorado River at the present-day California border after a grueling march across the province of New Mexico and the Sonoran Desert. Then, on 6 December 1846, they fought the botched, half-hour Battle of San Pasqual east of San Diego pueblo, where 21 of Kearny's troops were killed, the largest number of American casualties in the battles of the California Campaign.

Final conquest

Stockton rescued Kearny's surrounded forces and, with their combined force totaling 660 troops, they moved northward from San Diego, entering the Los Angeles Basin on 8 January 1847. On that day they fought the Californios in the Battle of Rio San Gabriel and the next day, in the Battle of La Mesa. The last significant body of Californios surrendered to American forces on 12 January 1847, marking the end of the war in Alta California.

After the California Campaign

Treaty of Cahuenga

The "Treaty of Cahuenga" was signed on January 13, 1847, and essentially terminated hostilities in Alta California. The treaty was drafted in English and Spanish by José Antonio Carrillo, approved by American Lieutenant-Colonel John C. Frémont and Mexican Governor Andrés Pico at Campo de Cahuenga, in the Cahuenga Pass of Los Angeles. It was later ratified by Frémont's superiors, Commodore Robert F. Stockton and General Stephen Kearny (brevet rank).

Pacific Coast Campaign

California Reinforcements

In July 1846, Colonel Jonathan D. Stevenson of New York was asked to raise a volunteer regiment of ten companies of 77 men each to go to California with the understanding that they would muster out and stay in California. They were designated the 1st Regiment of New York Volunteers and took part in the Pacific Coast Campaign. In August and September 1846 the regiment trained and prepared for the trip to California.

Three private merchant ships, Thomas H Perkins, Loo Choo, and Susan Drew, were chartered, and the sloop USS Preble was assigned convoy detail. On 26 September the four ships sailed for California. Fifty men who had been left behind for various reasons sailed on 13 November 1846 on the small storeship USS Brutus. The Susan Drew and Loo Choo reached Valparaíso, Chile by 20 January 1847 and they were on their way again by 23 January. The Perkins did not stop until San Francisco, reaching port on 6 March 1847. The Susan Drew arrived on 20 March and the Loo Choo arrived on 26 March 1847, 183 days after leaving New York. The Brutus finally arrived on 17 April 1847.

After desertions and deaths in transit the four ships brought 648 men to California. The companies were then deployed throughout Upper-Alta California, and Lower-Baja California on the Baja California Peninsula (captured by the Navy and later returned to Mexico), from San Francisco to La Paz. The ship Isabella sailed from Philadelphia on 16 August 1846, with a detachment of one hundred soldiers, and arrived in California on 18 February 1847 at about the same time that the ship Sweden arrived with another detachment of soldiers. These soldiers were added to the existing companies of Stevenson's 1st New York Volunteer Regiment. These troops essentially took over nearly all of the Pacific Squadron's on-shore military and garrison duties and the California Battalion's garrison duties.

In January 1847 Army lieutenant William Tecumseh Sherman and about 100 regular U.S. Army soldiers arrived in Monterey. American forces in the pipeline continued to dribble into California.

Mormon Battalion

Main article: Mormon Battalion

The Mormon Battalion served from July 1846 to July 1847 during the Mexican–American War. The battalion was a volunteer unit of between 534 and 559 Latter-day Saints men, who were led by Mormon company officers, commanded by regular United States Army senior officers. During its service, the battalion made a grueling march of some 1,900 miles from Council Bluffs, Iowa to San Diego. This remains one of the longest single military marches in U.S. history.

The Mormon Battalion arrived in San Diego on January 29, 1847. For the next five months until their discharge on July 16, 1847 in Los Angeles, the battalion trained and did garrison duties in several locations in southern California. Discharged members of the Mormon Battalion were helping to build a sawmill for John Sutter when gold was discovered there in January 1848, starting the California Gold Rush.

Treaty of Guadalupe Hidalgo

The Treaty of Guadalupe Hidalgo, signed in February, 1848, marked the end of the Mexican–American War. In that treaty, Mexico formally ceded Alta California along with its other northern territories east through Texas, receiving $15,000,000 in exchange. This largely unsettled territory constituted nearly half of its claimed territory with about 1% of its then population of about 4,500,000.

Timeline of events

Date	Events surrounding the United States' conquest of California
summer 1841	John C. Fremont was part of a U.S. Army topographical expedition to survey Iowa Territory.
19-Oct-1841	Fremont and Jessie Benton, daughter of U.S. Senator Thomas Benton of Missouri, were married.
summer 1842	Fremont led an expedition to survey the Oregon Trail in what is now Wyoming.
13-May-1843	Fremont departed St. Louis on a survey expedition to the mouth of the Columbia River in Oregon Territory.
Nov 1843	Fremont's expedition reached Fort Vancouver.
Jan 1844	Fremont's expedition crossed the Sierras into present-day California.
Mar 1844	Fremont reached Sutter's Fort, near present-day Sacramento.
01-Jul-1844	Nearing the end of the return trip, Fremont arrived at Bent's Fort, in what is now Colorado, after traveling through the San Joaquin Valley and Mojave Desert.
04-Mar-1845	James K. Polk was inaugurated as U.S. president.
21-Mar-1845	Navy Secretary George Bancroft sent a secret message to the port of Callou, Peru, ordering Commodore John D. Sloat, commander of the Navy's Pacific Squadron, to proceed to Mazatlan on the Mexican west coast.
May 1845	U.S. Navy flotilla commanded by Commodore Robert F. Stockton, on the warship Princeton, visited Galveston to gauge local attitudes for Texas annexation.
Jun 1845	Fremont's next Army survey expedition, approved earlier in the year by President Polk, left St. Louis on a mission to explore the Great Basin and Alta California.
Jun 1845	Commander John Sloat received Bancroft's orders to proceed from the Peruvian coast to Mexican waters.
mid-Jun 1845	War Secretary William Marcy sent orders to Brigadier General Zachary Taylor to move his 2000-man force from Ft. Jessup, Louisiana, to Corpus Christi, Texas. By October Taylor commanded 3500 men.
04-Jul-1845	Meeting in convention, leaders of the Republic of Texas approved an annexation treaty with the U.S.
16-Aug-1845	John C. Fremont, leading a U.S. Army topographical expedition to survey the Great Basin in Alta California, departed from Bent's Fort in what is now Colorado.
Oct 1845	Fremont's expedition reached the Salt Lake.
17-Oct-1845	Secretary of State James Buchanan dispatched a secret message to U.S. Consul Thomas Larkin in Monterey instructing him to take advantage of any sign of unrest among the Californians.
30-Oct-1845	President James K. Polk met with Lt. Archibald Gillespie to send him on a secret mission to California. He departed for Vera Cruz, Mexico, on November 16 carrying orders for Sloat, instructions for Larkin and letters for Fremont.
Nov 1845	General José Castro, the senior military officer in California, issued a decree ordering all American immigrants in Alta California (about 800) to proceed to Sonoma to swear an oath to Mexico and get a license to settle. 20 Americans later showed up at Sonoma.
Nov 1845	Commodore John D. Sloat, commander of the Navy's Pacific Squadron, then off Mazatlan, Mexico, was joined by the Cyane, which carried orders that if Sloat learned "beyond a doubt" that war between the U.S. and Mexico had begun, he was to seize San Francisco Bay and blockade the other California ports.
11-Nov-1845	General Castro visited Colonel Mariano Vallejo, commandante of the Mexican garrison in Sonoma.
16-Nov-1845	Lt. Archibald Gillespie departed Washington for Vera Cruz, Mexico.
27-Nov-1845	The two parts of Fremont's split party had a rendezvous at Walker Lake, northeast of Yosemite Valley.
Dec 1845	The Fremont expedition entered the Sacramento Valley.
10-Dec-1845	Splitting up once more, Fremont and 16 others (including scout Kit Carson) reached Sutter's Fort.
29-Dec-1845	President Polk signed legislation admitting Texas to the Union. Mexico refused to recognize the U.S. annexation.
Jan 1846	John Slidell, appointed by Polk, arrived in Vera Cruz on a mission to negotiate a boundary agreement, and, if Mexico demonstrated a willingness to sell its departments of New Mexico and California, to offer up to $40 million for them.
Jan 1846	Fremont and his smaller group crossed the San Joaquin Valley to Monterey.
27-Jan-1846	Fremont visited Thomas Larkin, the U.S. Consul in Monterey. Fremont also met Jose Castro, who agreed to let Fremont winter in the San Joaquin Valley, away from the coast.
mid-Feb 1846	Fremont met up with the other 45 men in his party and traveled north to the vicinity of the San Jose Mission.
05-Mar-1846	After moving his camp to Santa Cruz, Fremont moved it again closer to Monterey on the Salinas River. Via courier, General Castro ordered Fremont to leave. Fremont then set up camp at Gavilan Peak, near San Juan Bautista.
06-Mar-1846	Mexican president José Herrera rejected all points of Slidell's proposed negotiation.
08-Mar-1846	General Castro assembled a cavalry force of nearly 200 men to confront Fremont near San Luis Bautista.
08-Mar-1846	Zachary Taylor moved his army across the Nueces River in Texas, which Mexico considered as the southern border of its department of Texas.
09-Mar-1846	After receiving a message from Larkin not to oppose Castro, Fremont's band left Gavilan Peak and headed for Sutter's Fort.
mid-Mar 1846	Larkin sent a message to Sloat at Mazatlán asking one of his ships to come to Monterey. Sloat sent the Portsmouth, John B. Montgomery commanding. Montgomery was tasked to distribute copies of the U.S. and Texas constitutions in Spanish.
21-Mar-1846	Fremont arrived at Sutter's Fort to ready a further expedition to the Oregon Territory.
28-Mar-1846	Zachary Taylor's force arrived at the Rio Grande near Matamoros.
30-Mar-1846	Fremont's party reached Rancho Bosquejo on Deer Creek, 200 miles north of Sutter's Fort. His tentative plan was to map a route from the western slope of the Cascades across the Great Basin to link with the Oregon Trail. (Historians have suggested this was a calculated delaying tactic.)
end Mar 1846	Alarmed by Fremont's transgression at Gavilan Peak, General Jose Castro called a military council in Monterey.
17-Apr-1846	In Monterey, Larkin met with Lt. Gillespie, who had finally arrived in Monterey via Honolulu on the Cyane.
17-Apr-1846	In Monterey, Mexico issued a proclamation that unnaturalized foreigners were no longer permitted to hold or work land in California and were subject to expulsion.
21-Apr-1846	The Portsmouth anchored in Monterey Bay.
24-Apr-1846	Mexican President Mariano Rivera y Arrillaga (who had deposed Herrera), having earlier sent a 5,000-man army northward to Texas, declared a "defensive war" against the United States. Also, the Mexican army arrived in Matamoros on the Rio Grande on April 24.
25-Apr-1846	Troops under Zachary Taylor and Mexican General Mariano Arista skirmished north of the Rio Grande. 16 Americans were killed, after which Taylor communicated the events in a message sent to Washington.
08-May-1846	Fremont, then camped at Upper Klamath Lake in Oregon Territory, learned that a military man (Gillespie) was riding north to intercept him.
08-May-1846	At Palo Alto on the Rio Grande in Texas, an artillery battle lasted from 2:30 p.m. to night fall. 5 Americans died, 43 wounded, and over 30 Mexicans were killed.
09-May-1846	Fremont met with Gillespie and received letters from wife Jessie, Senator Benton and Secretary of State James Buchanan, as well as Gillespie's memorized messages from Polk, Benton and Larkin.
09-May-1846	At the Rio Grande, the U.S. and Mexican armies met at Reseca de la Palma. Arista's army was routed, leaving behind 400 wounded. 33 Americans died, 89 were wounded.
09-May-1846	President Polk received General Taylor's April 25 message.
10-May-1846	While asleep in the early morning hours, the Fremont camp was attacked by Klamath Indians, killing three of Fremont's party. The Klamath chief was shot dead during the fight.
12-May-1846	The Fremont party attacked a Klamath village, killing 14 Indians and burning the lodges. The expedition turned back toward California.
13-May-1846	The United States Congress voted overwhelmingly to declare war on Mexico. Definitive word of the declaration reached California in August.
13-May-1846	The war secretary sent orders to Colonel Stephen Kearny at Fort Leavenworth, in what is now Kansas, to march west to conquer and occupy the Mexican departments of New Mexico and California.
18-May-1846	General Taylor's army entered Mexico and occupied Matamoros.
18-May-1846	Commander Sloat in Mazatlan received detailed news of Taylor's army fighting at the Rio Grande.
24-May-1846	On its way south, the Fremont expedition reached Peter Lassen's ranch and learned that the Portsmouth was anchored at Sausalito. Lt. Gillespie was sent to request supplies (8000 percussion caps, 300 pounds of rifle lead, one keg of powder and food provisions) from Montgomery and to continue on to Monterey to inform Larkin that the expedition would be heading back to St. Louis.
31-May-1846	Fremont's party, along with Gillespie and his escort, camped at the Buttes, 60 miles north of Sutter's Fort.
late May 1846	With rumors swirling that General Castro was massing an army against them, American settlers in the Sacramento Valley banded together to meet the threat.
31-May-1846	Sloat received trustworthy news of Taylor's battles of May 8-9. His orders required him to sail north upon learning "without a doubt" that war had been declared.
early Jun 1846	Believing that war with Mexico was a virtual certainty, Fremont joined the Sacramento Valley rebels in a "silent partnership."
early Jun 1846	John Sutter, a Swiss who was a naturalized Mexican citizen, notified his immediate superior, General Castro, of Gillespie's true identity and urged Castro to send a respectable garrison north in the event of trouble.
05-Jun-1846	Jose Castro again visited Mariano Vallejo in Sonoma and collected horses and supplies for his men from Vallejo's ranch.
07-Jun-1846	Sloat received news that an American squadron had blockaded Vera Cruz.
08-Jun-1846	Among the settlers, William Knight visited William Ide to report the rumor that "armed Spaniards on horseback" had been seen in the valley. The two rode to Fremont's camp north of New Helvetia. Another report to Fremont said that Lt. Francisco Arce, militia officer Jose Maria Alviso, and eight armed men were near Sutter's Fort, driving a herd of 170 horses, destined for Santa Clara.
08-Jun-1846	Sloat set sail for Monterey on the Savannah.
10-Jun-1846	Four men from Fremont's party and 10 volunteers rode out to intercept Arce, surprised him and seized the horse herd, thus initiating the open rebellion of the Osos.
11-Jun-1846	The Americans drove the herd north to the Buttes camp, gathering a dozen new volunteers. (Historian H. H. Bancroft later wrote that Fremont "instigated and planned" the horse raid, and incited the American settlers indirectly and "guardedly" to revolt.)
13-Jun-1846	34 armed men (none was from Fremont's party) rode from the Buttes to seize the town of Sonoma, force the surrender of Colonel Vallejo, and thus forestall Castro's plan to harry the settlers and force them to leave Mexico. The Osos knew that Sonoma had had no garrison for a year and no finances for one.
14-Jun-1846	The Osos entered Sonoma at dawn, rode to Vallejo's Casa Grande and knocked on the door. Vallejo served the Oso leaders food and brandy during a 3 hour period in which surrender documents were drafted, with provisions for the Americans to respect the townspeople and their property. Several Osos rejected the surrender. Ezekiel Merritt and John Grigsby asserted that Fremont had ordered the capture of Sonoma. William Ide beseeched his fellow insurgents to keep themselves under control. 24 Osos stood with him and elected him their leader. William Todd fashioned the Bear Flag, which was later raised in Sonoma Plaza. Ten men were selected to escort four prisoners taken from the Vallejo's homestead, including Mariano Vallejo, to the American camp, 80 miles away.
14-Jun-1846	Fremont and his band rode to Sutter's Fort, not yet aware of the raid's outcome, to receive the supplies that were requested from Montgomery.
15-Jun-1846	The Oregon Territory convention was signed by England and the U.S., ending its joint occupation with England and making most Oregonians below the 49th parallel American citizens.
15-Jun-1846	William Ide proclaimed his "Bear Flag Manifesto." Within a week, over 70 more American volunteers joined the Osos.
15-Jun-1846	Ide sent Todd to the Portsmouth to notify Montgomery of the events in Sonoma. Todd also requested gunpowder, which was denied.
16-Jun-1846	Prisoners and escorts arrived at Fremont's camp. Fremont denied responsibility for the raid. The escorts removed the prisoners to Sutter's Fort. Fremont began signing letters as "Military Commander of U.S. Forces in California."
16-Jun-1846	John Montgomery of the Portsmouth in Sausalito sent a small landing party to Sonoma. Ide, in his first act as commander-in-chief, reappointed Jose Berryessa alcalde, to continue as local magistrate.
16-Jun-1846	Todd returned to Sonoma. He and a companion were then assigned to ride toward Bodega Bay to obtain arms and powder from American settlers.
17-Jun-1846	General Castro and Pio Pico, governor of Alta California, condemned the takeover.
18-Jun-1846	Thomas Cowie and George Fowler were sent to Rancho Sotoyome (near modern-day Healdsburg) to pick up a cache of gunpowder from Moses Carson, brother of Frémont's scout.
20-Jun-1846	After both parties failed to return, a 5-man group obtained powder and also learned from a captured Californian that Cowie and Fowler were tortured and murdered by a patrol of California "irregulars" near Santa Rosa, led by Juan Padilla, and that Todd and his companion had been taken prisoner.
23-Jun-1846	50 to 60 men under Captain Joaquin de la Torre traveled to San Pablo and crossed the San Francisco Bay by boat to Point San Quentin.
23-Jun-1846	Led by Henry Ford, about 20 Osos rode toward Santa Rosa to search for the two captives and Padilla's men.
24-Jun-1846	The search party captured four Californians near San Antonio and also found a corral of horses at Olompali, near the mouth of the Petaluma River, which they assumed belonged to Padilla's group. When they approached the ranchhouse, they discovered about 50 uniformed Californio lancers, in addition to Padilla's group, under the command of Captain Joaquin de la Torre. Ford's men opened fire from a distance, killing one and wounding one. Todd and his partner escaped, while the Californios returned to San Rafael and the Osos went to Sonoma. The "Battle of Olompali" was the only fight of the Bear Flag Republic.
25-Jun-1846	After learning of Cowie, Fowler and Ford's patrol, Fremont and his men rode to Sonoma.
26-Jun-1846	Fremont, Ford and a detachment of Osos rode south to San Rafael, but were unable to locate de la Torre and his Californios.
27-Jun-1846	Two additional divisions of General Castro's troops with a total of about 100 men arrived at San Pablo.
28-Jun-1846	General Castro, on the other side of San Francisco Bay, sent a boat across to Point San Pablo with a message for de la Torre. Kit Carson, Granville Swift and Sam Neal rode to the beach to intercept the three unarmed men who came ashore. Two 20-year-old twin brothers and the father of Jose Berryessa were then murdered in cold blood.
28-Jun-1846	Fremont's men intercepted a messenger with a letter advising Castro that de la Torre was about to attack Sonoma. Fremont and his forces immediately went there, only to find the Osos prepared to fire upon them as they approached.
29-Jun-1846	Realizing he had been tricked, Fremont hurried back to San Rafael and Sausalito in pursuit of de la Torre and his men, who had escaped across the bay and joined Castro in a retreat to Santa Clara.
01-Jul-1846	The merchant ship Moscow transported Fremont and several others from Sausalito to Castillo de San Joaquin, an abandoned fort south of the entrance to San Francisco Bay, where they plugged the touch-holes of ten rusty cannons.
01-Jul-1846	Sloat reached Monterey harbor
02-Jul-1846	Several Osos occupied Yerba Buena without resistance.
04-Jul-1846	The Bear Flaggers, including Fremont and his men, celebrated Independence Day in Sonoma.
04-Jul-1846	Sloat met with Larkin in Monterey.
05-Jul-1846	Ide's rebels numbered nearly 300. Fremont, Ide and their officers met to discuss strategy. Fremont announced that a disciplined army was to be formed, which he volunteered to command, by combining his and the Osos' forces. In order to march south, engage Castro and any other Californians, the California Battalion, as it came to be called, combined Fremont's original exploring party and over 200 rebels, Sutter workers and local Indians.
05-Jul-1846	Sloat received a message from Montgomery reporting the events in Sonoma and Fremont's involvement.
06-Jul-1846	One of the four companies of the California Battalion remained in Sonoma, as the other three left with Fremont for the camp near Sutter's Fort, where they planned the campaign against Castro and the other Californios.
06-Jul-1846	Believing Fremont to be acting on orders from Washington, Sloat began to carry out his orders.
07-Jul-1846	A landing party demanded the surrender of Monterey. An artillery officer in charge refused. Sloat then landed 225 sailors and marines on the beach. Within minutes the American flag was hoisted, the American ships' cannons added a 21-gun salute, and Sloat read his proclamation of the annexation of Alta California to the United States. A messenger was sent to General Castro at San Juan Bautista requesting his surrender. No shots had been fired.
09-Jul-1846	Castro answered in the negative.
09-Jul-1846	At 8:00 a.m., Lt. Joseph Warren Revere, with 70 sailors and marines, landed at Yerba Buena, raised the American flag and claimed San Francisco Bay for the United States, and read Sloat's proclamation. No Mexican officials were in Yerba Buena.
09-Jul-1846	Later that day, Revere repeated this ceremony in Sonoma Plaza. The Bear Flag was lowered, and the American flag was raised in its place. The 25-day Bear Flag Republic ended.
10-Jul-1846	At his camp, Fremont received a message from Montgomery on the U.S. Navy's occupation of Monterey and Yerba Buena.
12-Jul-1846	The American flag flew above Sutter's Fort and Bodega Bay.
12-Jul-1846	Fremont's party, including the Bear Flaggers, rode into New Helvetia, where a letter from Sloat awaited, describing the capture of Monterey and ordering Fremont to bring at least 100 armed men to Monterey. Fremont would bring 160 men.
15-Jul-1846	Commodore Robert Field Stockton arrived in Monterey to replace the 65-year-old Sloat in command of the Pacific Squadron. Sloat named Stockton commander-in-chief of all land forces in California.
16-Jul-1846	Fremont raised the U.S. flag over San Juan Bautista.
16-Jul-1846	Governor Pico issued a proclamation on the American invasion and a conscription order for Mexican citizens, which produced about 100 men to join with Castro's force.
19-Jul-1846	Fremont's party entered Monterey. Fremont met with Sloat on board the Savannah. When Sloat learned that Fremont had acted on his own authority, he retired to his cabin.
23-Jul-1846	Stockton mustered Fremont's party and the former Bear Flaggers into military service as the "Naval Battalion of Mounted Volunteer Riflemen" with Fremont in command.
26-Jul-1846	Stockton ordered Fremont and his battalion to San Diego to prepare to move northward to Los Angeles.
29-Jul-1846	Sloat ordered the release of Vallejo and the other prisoners at Sutter's Fort. Sloat turned command over to Stockton and left for home. Stockton issued a proclamation annexing California to the U.S. General Castro in Santa Clara subsequently began to move south to Los Angeles with about 100 men.
29-Jul-1846	The battalion landed and raised the U.S. flag in San Diego.
end Jul-1846	A garrison of Stockton's men raised the U.S. flag at Santa Barbara.
01-Aug-1846	An ill and much thinner Vallejo was released from Sutter's Fort. While in confinement, 1000 of his cattle and 600 horses were stolen.
01-Aug-1846	Stockton's 360 men arrived in San Pedro.
02-Aug-1846	Two representatives of Castro arrived at Stockton's camp with a message expressing Castro's willingness to negotiate for peace. Stockton rejected the terms of the letter.
07-Aug-1846	Stockton penned a return message to Castro, who also rejected its terms, including that California cease to be part of Mexico.
09-Aug-1846	Castro held a war council at La Mesa, expressed doubts about his forces, and wrote a farewell address to the people of California. Governor Pico read Castro's message to the legislature in Los Angeles, which then adjourned sine die. Pico penned an open farewell letter.
10-Aug-1846	Castro and 20 men rode toward the Colorado River and reached the Mexican state of Sonora in September. Pico left to hide out in San Juan Capistrano for one month and eventually made his way to Baja California and Sonora.
13-Aug-1846	Stockton's army entered Los Angeles unopposed.
17-Aug-1846	Stockton issued a proclamation announcing that California was now part of the United States.
22-Aug-1846	Stockton sent a report to Secretary of State Bancroft that "California is entirely free from Mexican dominion."
02-Sep-1846	Stockton divided California into three military districts.
05-Sep-1846	Stockton, his sailors and marines set sail for Monterey.
23-Sep-1846	In Los Angeles, 20 California irregulars under militia captain Cerbulo Varela, chafing under Archibald Gillespie's tyrannical administration of martial law, assaulted the barracks of the small U.S. garrison and were repulsed.
25-Sep-1846	Stephen Kearny's 300-man force departed from Santa Fe.
27-Sep-1846	Californios skirmished with and captured 24 Americans led by Benjamin D. Wilson, who were hiding at Rancho Santa Ana del Chino, and suffered one dead.
29-Sep-1846	The rebel forces grew to 300 and demanded Gillespie's surrender in a manifesto. General Jose Maria Flores offered to let the Americans leave unharmed. Gillespie's garrison surrendered, taking refuge at San Pedro Bay on a merchant ship.
01-Oct-1846	At Yerba Buena, Stockton received news of the insurrection of armed Californians in Los Angeles and its impending fall.
01-Oct-1846	Fifty of Flores' men took San Diego when the small American garrison of less than 20 men retreated. At Santa Barbara, the 10-man U.S. garrison also surrendered the town and escaped under pressure.
06-Oct-1846	Ten miles south of Socorro, New Mexico, the eastern-bound Kit Carson and his express party encountered Kearny's forces heading west. Upon learning California had easily fallen, Kearny sent 200 of his 300 men back to Santa Fe. Kearny ordered Carson to guide his reduced force to San Diego.
07-Oct-1846	Captain William Mervine landed 350 sailors and marines at San Pedro.
08-Oct-1846	The "Battle of the Old Woman's Gun" (a Mexican four-pounder cannon) occurred north of Rancho Dominguez between forces of Flores and Mervine; it lasted less than an hour. Four Americans died, and 8 were severely injured in the ambush. Mervine's forces returned to San Pedro Bay, where Mervine's warship then departed toward Monterey.
11-Oct-1846	Fremont and 170 men arrived at Yerba Buena.
12-Oct-1846	Stockton departed for San Pedro with his forces on the Congress.
23-Oct-1846	Stockton arrived at San Pedro, finding that Mervine's ship had returned. The American forces thus grew to 800 in San Pedro.
27-Oct-1846	Fremont and his men arrived in Monterey after sailing from Yerba Buena, in order to gather horses and volunteers.
late Oct 1846	The tiny American garrison that fled San Diego several weeks earlier landed a short distance from San Diego and re-took the village after firing three small cannons at Flores' men.
end Oct 1846	Stockton and Mervine arrived at San Diego with their forces to set up a base of operations.
16-Nov-1846	A skirmish, the "Battle of la Natividad [Rancho]," occurred near San Juan Bautista between California Battalion troops en route to Monterey and 130 Californians. Five to seven Americans and two Californians died.
22-Nov-1846	Kearny's 100-man force learned from Mexican herders that Los Angeles had been taken away from the Americans.
30-Nov-1846	Fremont, 430 men and 2000 horses and mules started out for Los Angeles.
02-Dec-1846	Kearny reached Warner's Ranch, 50 miles northeast of San Diego.
03-Dec-1846	Stockton received a message from Kearny and sent Gillespie and a 35-man patrol riding out to meet him.
05-Dec-1846	Gillespie's party met up with Kearny's forces, who were riding from Santa Ysabel to San Pascual (near the modern town of Ramona, CA). Gillespie told Kearny that 100 soldiers under Captain Andres Pico (younger brother of the deposed governor) were posted 10 miles ahead.
05-Dec-1846	An 8-man night horseback patrol botched a reconnaissance, tipping off the Mexican forces to their presence.
06-Dec-1846	Kearny's army of about 150 men approached San Pascual at dawn, strung out nearly a mile, while Pico's men lied in wait. The battle began by mistake when a captain misheard a Kearny order and began a charge, opening gaps in the line of march. The battle lasted 30 minutes, ten of them in hand-to-hand combat, ending when two American howitzers at the rear of the line finally began firing. 22 Americans, including three officers, died (20 by lance wounds). Mexican casualties as reported by Pico were 11 wounded; as reported by Kearny, 6 dead on the field.
07-Dec-1846	Three men left camp to deliver a message to Stockton and were captured by Pico on their way back from San Diego. The wounded Kearny and his remaining force reached the San Bernardo riverbed and encountered a detachment of lancers, who opened fire. Kearny's forces scrambled up a low hill (later called "Mule Hill" by the soldiers) and repulsed the Californians in a brief skirmish, with no American casualties. However, Pico kept the hill under siege.
08-Dec-1846	A prisoner exchange (one each) occurred, with 2 Americans remaining as prisoners.
08-Dec-1846	A three-man messenger party (including Kit Carson) left the hill at dusk, splitting up.
08-Dec-1846	At Yerba Buena, a small band of Californians seized the acting alcade, Lt. Washington Bartlett.
09-Dec-1846	An American sergeant wounded at San Pascual died of his wounds at Mule Hill.
09-Dec-1846	The three messengers reached San Diego and Commodore Stockton separately on 12/9, 10 and 11.
11-Dec-1846	A 215-man American relief expedition reached Mule Hill before dawn.
11-Dec-1846	The 350-man American force rode to San Bernardo Rancho. Pico, with his forces reinforced to 250 men but facing superior numbers, abandoned the field before the Americans' arrival, leaving his army's cattle herd behind.
14-Dec-1846	Fremont and the 428-man California Battalionarrived in San Luis Obispo and captured several local officials who were still in contact with General Flores.
16-Dec-1846	The prisoners were freed, in order to allow word of Fremont's overwhelming numbers to spread before them.
17-Dec-1846	Fremont resumed his march to Los Angeles.
27-Dec-1846	Fremont reached a deserted Santa Barbara and raised the American flag.
28-Dec-1846	The 600-man Army of the West under Kearny began a 150-mile march to Los Angeles.
late Dec-1846	Fremont occupied a hotel close to the adobe of Bernarda Ruiz de Rodriguez, a wealthy educated woman of influence and Santa Barbara town matriarch, who had four sons on the Mexican side. She asked for and was granted ten minutes of Fremont's time, which stretched to two hours; she advised him that a generous peace would be to his political advantage -- one that included Pico's pardon, release of prisoners, equal rights for all Californians and respect of property rights. Fremont later wrote, "I found that her object was to use her influence to put an end to the war, and to do so upon such just and friendly terms of compromise as would make the peace acceptable and enduring. ... She wished me to take into my mind this plan of settlement, to which she would influence her people; meantime, she urged me to hold my hand, so far as possible. ... I assured her I would bear her wishes in mind when the occasion came." The next day, Bernarda accompanied Fremont south.
early Jan 1847	General Flores headquartered at San Fernando with 500 poorly equipped men.
02-Jan-1847	A party of American marines and sailors skirmished with a force of 120 Californians at Yerba Buena under Francisco Sanchez. Four Californians died.
03-Jan-1847	At Yerba Buena, Sanchez agreed to a cease-fire.
04-Jan-1847	The Stockton-Kearny force reached San Luis Rey. Stockton rejected a cease-fire proposal that was sent under a truce flag from General Flores. They proceeded toward San Juan Capistrano. A message to Stockton told of Fremont's presence at Santa Barbara.
05-Jan-1847	Frémont, near the San Buenaventura Mission with the California Battalion and six field pieces, dispersed a force of 60-70 Californio lancers.
06-Jan-1847	At Yerba Buena, Sanchez surrendered unconditionally.
07-Jan-1847	Flores moved his force to a 50-foot-high bluff above the San Gabriel River, 12 miles northeast of Los Angeles.
08-Jan-1847	Stockton's army advanced toward the Californians' position and began crossing the river. Musket and cannon fire by Flores' forces, handicapped by poor quality powder, inflicted few casualties. Following the crossing and destructive American cannon fire, Kearny's men began their charge up the hill, and the Californians retreated. The Battle of San Gabriel lasted two hours. Two American sailors were killed, with 8 men wounded.
08-Jan-1847	Fremont arrived at San Fernando.
09-Jan-1847	The Stockton-Kearny army resumed their march and met a smaller force of Flores' men. Following a 2 1/2 hour fight, the Americans won the Battle of La Mesa, suffering only five wounded. The army then camped three miles from Los Angeles.
10-Jan-1847	The army entered Los Angeles with no resistance, and Gillespie raised the U.S. flag over his old headquarters.
11-Jan-1847	Fremont learned of the reoccupation of Los Angeles.
11-Jan-1847	Flores turned over his command to Andres Pico and fled toward Sonora.
12-Jan-1847	Bernarda went alone to Pico's camp and told him of the peace agreement she and Fremont had forged. Fremont and two of Pico's officers agreed to the terms for a surrender, and Articles of Capitulation were penned by Jose Antonio Carrillo in both English and Spanish . The first seven articles in the treaty were nearly the verbatim suggestions offered by Bernarda Ruiz de Rodriguez.
13-Jan-1847	At a deserted rancho at the north end of Cahuenga Pass (modern-day North Hollywood), with Bernarda Ruiz de Rodriguez present, John Fremont, Andres Pico and six others signed the Articles of Capitulation, which became known as the Treaty of Cahuenga. This unofficial truce, which did not have the backing of the American government and had nothing to do with the Mexican government, was honored by both the Americans and Californios. Fighting ceased, thus ending the war in California.
14-Jan-1847	The California Battalion entered Los Angeles in a rainstorm.
15-Jan-1847	Stockton approved the Treaty of Cahuenga in a message sent to Navy Secretary Bancroft.
14-Sep-1847	The US Army stormed Chapultapec Castle, the last major military action of the war. In winning the war, 13,000 Americans died during its 17 months, 1700 of them from wounds sustained in battle. 11,300 others died mainly from disease.

See also

• California Campaign topics
• Mexican California topics
• Mexican–American War
  • Pacific Coast Campaign
• History of California through 1899
• Indigenous peoples of California

Further reading

• Hubert Howe Bancroft. The Works of Hubert Howe Bancroft, vol 22 (1886), History of California 1846-48; complete text online; famous, highly detailed narrative written in 1880s. Also at History of California, VOL. V., 1846-1848
• Harlow, Neal California Conquered: The Annexation of a Mexican Province 1846–1850, ISBN 0-520-06605-7, (1982)
• Hittell, Theodore Henry. History of California vol 2 (1885) online
• Nevins, Allan. Fremont: Pathmarker of the West, Volume 1: Fremont the Explorer (1939, rev ed. 1955)
• Rawls, James and Walton Bean. California: An Interpretive History (8th ed 2003), college textbook; the latest version of Bean's solid 1968 text

External links

Media related to California Campaign at Wikimedia Commons

• A Continent Divided: The U.S. - Mexico War — from the Center for Greater Southwestern Studies, the University of Texas at Arlington.
• Map of Mexico and the United States during the California Campaign at omniatlas.com