In what year did California become a state in the Union?

California became a state in the Union in 1850 as part of the series of events following the Gold Rush, which began in 1848. The rapid influx of settlers seeking fortune led to a significant population increase, prompting California to apply for statehood. On September 9, 1850, California was admitted as the 31st state, making it the first state on the West Coast to join the Union. This event was significant as it also played a crucial role in the debates over slavery during that period, influencing the balance of power between free and slave states.

The dates provided for the other options do not correspond to California's statehood; 1862 pertains to other historical events, while 1902 and 1890 are also not related to California's admission.