Bidwell-Bartleson party became first organized group of American settlers to travel to California by land
The early 1840s brought the first large overland party of Americans from the Midwest to California. American trappers had previously come to California in small groups, but had not settled. In 1840 a 20-year-old schoolteacher named John Bidwell helped to organize the Western Emigration Society in Missouri. He had heard tales from trappers of how warm and inviting the climate of California was, and he gathered together people who wanted to go there.
Some 69 Americans left Missouri in May 1841, bound for California. Among them were settlers, adventurers, missionaries, and families, a mixed group of people traveling for different purposes but all intent on reaching California. They selected John Bartleson as their captain, but he soon became known for his mistakes and poor leadership. John Bidwell took over the command during key moments, and the party arrived in California at the ranch of John Marsh near Mt. Diablo on November 4, 1841. They were destitute and hungry from the six-month journey, barely getting through the Sierra Nevada Mountains before the heavy snows. Bidwell found a job at Sutter’s Fort, and later became a leader among early California pioneers.
"Bear Flag" revolt led to breakdown of Mexican authority in California
The 1840s saw the end of Mexican control over California, a process that started with the "Bear Flag" revolt of 1846. Knowing that U.S. President James Polk was interested in acquiring California, U.S. Army Captain John Frémont set up camp in the Sacramento Valley north of Sutter’s Fort. Some American settlers who got wind of the news began to rally together. On June 10 they launched a revolt against Mexican authority by stealing a herd of horses; on June 14 they captured General Vallejo, commander of Mexican forces in Northern California.
They became known as the Bear Flaggers because they raised a flag with a grizzly bear and one star on a field of white, bordered at the bottom by a red stripe, as the standard of the "California Republic," with William B. Ide as president of the republic. They fought only one battle, the Battle of Olompali, in which two Californians were killed. Captain Frémont then announced his support of the revolt. By this time, the U.S. was at war with Mexico. American ships arrived at Monterey on July 7 and the American flag was raised. The Bear Flag Republic was at an end.
Marshall discovered gold at Sutter's Mill and the gold rush started
In 1848, James Wilson Marshall discovered gold in Coloma. Thus began the great gold rush of 1849, from which the term "Forty-Niner" comes. Marshall was a young wagon builder from New Jersey who came overland to work in a sawmill. On January 24, 1848, while inspecting the tailrace of the mill, he saw a piece of metal shining in the water. Once he picked it out and realized that it was soft, he knew he had found gold. Over the next day he collected three ounces of gold, which he showed to his employer, John Sutter.
They tried to keep the secret, but word soon spread. By June of 1848 almost no men remained in Monterey, San Francisco, San Jose, or Santa Cruz. Everyone wanted to find gold. Soldiers deserted, as did their reinforcements; seamen left their ships lying in the harbors; farmers and merchants abandoned their trades and left for the hills. Eventually the stream of people would increase the population of California from 15,000 to 92,597 by 1850, and 379,994 by 1860. The migration was the largest in the western world since the Crusades, drawing people not only from North America but from around the world. Shanty-towns sprang up throughout the hills, and some miners averaged over $50 a day prospecting.
Mexico gave California to the United States by the Treaty of Guadalupe Hidalgo
In February of 1848, Mexico ceded Alta (Upper) California to the United States in the Treaty of Guadalupe Hidalgo. Mexico and the U.S. had been at war primarily over control of Texas, but there were already Americans in California who were revolting. President Polk, who wanted to annex California, sent 350 men by ship and 300 more overland from Santa Fe to accomplish the task. General Castro and Governor Píco, leaders of the Mexican forces there, retreated in the face of such opposition, and the Americans took Los Angeles and San Francisco. However, the Mexican settlers put up a more spirited resistance. They forced the Americans out of Los Angeles and fought skirmishes with them until the battles of San Gabriel and La Mesa, on January 8 and 9, 1848. Here the Mexicans were decisively defeated, and they surrendered.
In the Mexican town of Guadalupe Hidalgo on February 2, 1848, the U.S. and Mexico signed the Treaty of Guadalupe Hidalgo, giving the U.S. control over most of California but returning Baja (Lower) California, which was not heavily populated by Americans, to Mexico.