California was populated by many Native American tribes before European exploration began in 1542. Spanish settlers built a string of missions up California’s coast, about a day’s journey from one another, along El Camino Real.
Mexico took control of the territory from Spain in 1821, and controlled it for 25 years until the Mexican-American War began in 1846.
The Treaty of Guadalupe Hidalgo ended the Mexican-American War, and several territories were ceded to the United States, including California.
On June 14, 1846, the California Republic was formed as an independent state.
By January 1847, the United States completely occupied California, but the the territory didn’t become a state until it was admitted to the Union as the 31st state on September 9, 1850.
The United States was divided on the issue of slavery around the time they voted on admitting California to the Union, so the idea of adding territories to the Union intensified the debate.
California was divided on the issue of slavery because many Southerners had moved to California with their slaves during the Gold Rush in 1849. California decided to be a free state.
Southerners, who wanted slavery to continue, voted against California becoming a state, because California decided to remain a free state. Northerners pushed for California to become a state and won.
Though California had entered the Union as a free state, the state’s constitution denied many civil rights to non-white citizens.
Southern California tried to separate from Northern California because they were not satisfied with the taxes, land laws, and stance on slavery. Southern California’s 3rd attempt almost succeeded, but was never voted on once Lincoln was elected president. At the outbreak of the Civil War, Southern Californians joined the Confederacy, and flew the Bear Flag in revolt.
California’s history and relationship with Mexico have shaped the state in the literal sense, forming its boundaries. California continues to define itself, and has become one of the most influential and powerful states in the country, and even the world.