Before the United States formally invaded and conquered California, it was a province of Mexico. In the 1840s, a band of Yankee freebooters seized the Golden State and robbed it of its independence.
The Californios were not the only people ripped off; Native American tribes in California also suffered a great deal of dispossession from white settlers. This led to a series of conflicts between Indians and Americans, especially in the early 1850s.

John C. Fremont
As the explorer who led the conquest of California, John C. Fremont became known as “The Pathfinder” and a national celebrity. His exploits were so successful that they were able to transform him into one of the founding members of the nascent Republican Party in 1856, which became the most powerful political party in the United States.
When President Polk declared war with Mexico in October 1846, Fremont was at the forefront of the U.S. naval campaign to occupy California and southwestern ports.
Despite his pronounced anti-slavery views, Fremont was elected to the Senate in 1849 and later served as a member of the first Republican President's cabinet. In 1860, the United States entered into the Civil War, and Fremont was given command of the Department of the West.
After the war, Fremont settled in the state of California with his wife Jessie, the daughter of Missouri politician Thomas Hart Benton. His anti-slavery stance made him an attractive candidate for the nascent Republican Party, and he lost to Democrat James Buchanan in the presidential election of 1856.
Robert Field Stockton
During the Mexican-American War, Commodore Robert Field Stockton led United States Navy forces in the conquest of California. He was a naval innovator and an early advocate for a propeller-driven, steam-powered navy. He was also a prominent political figure and member of a well-known political family.
Originally from Princeton, N.J., he was the grandson of Declaration of Independence signer Richard Stockton Sr. He began his naval career as a midshipman aboard the President, flagship of Commodore John Rodgers.
He later commanded naval forces in the Eastern Pacific, and during the Mexican-American War he was instrumental in taking California from Mexico. He also played a pivotal role in the annexation of Texas to the United States.
He was also known for his contributions to both the colonization movement and the eradication of the African slave trade. Newspapers regularly praised him for these endeavors, and the people of California named their city after him.
Stephen W. Kearney
Kearney and his cavalry regiment played a central role in securing the Southwest for the United States in 1846-1847. They were tasked with protecting the frontier, escorting settlers along the Oregon and Santa Fe Trails, and patrolling the Great Plains.
Kearny and his men were on their way west when they encountered news of a Californio rebellion in Los Angeles. In December of that year, he arrived at an Indian village called San Pasqual and engaged Andre Pico’s Californio lancers in battle.
He lost 18 men and his command was badly outnumbered. He then retreated and was rescued by Stockton’s troops from San Diego.
After a brief period in military governorship, Kearny returned east to Fort Leavenworth, Kansas. He served in that post until 1847 when he was sent to Mexico as the civil governor of Vera Cruz and later Mexico City.
Los Angeles
In 1781, a party of Chumash and Tongva Native American settlers journeyed more than one-thousand miles across the desert to establish El Pueblo de Nuestra Senora la Reina de los Angeles de Porciuncula, or Los Angeles, as it was called in Spanish. It soon grew to become a major farming town, but Los Angeles’s expansion would depend on gaining access to water.
Despite the Los Angeles River’s unpredictable nature, city boosters knew they needed more reliable water supplies to grow the city into an affluent metropolis. So they devised a plan to gain the water rights to Owens Lake, 200 miles away high in the Sierra Nevada.
The resulting network of electric trains connected the San Fernando Valley and Santa Monica to downtown LA, allowing residents to travel inland as far as San Bernardino and Redlands for a penny per mile. This helped the city spread into the arid basin and transform itself from a town of farms to an international multi-racial world metropolis.