On September 16, 1810, Mexico declared its independence from Spain. However, Mexico’s war for independence continued for another 11 years ending with the Treaty of Córdoba in August 1821. Mexico in the 1820s, up until the Mexican-American War in 1846, was divided into two provinces: Baja California (what is the country of Mexico today) and Alta California (today the states of California, Arizona, New Mexico, Utah, and parts of Colorado and Wyoming). Alta California, however, often saw itself sep