From 1823 to 1834, Catholic mission life dominated Sonoma, while the land before it had earlier been an open field where Miwok Native Americans hunted with bow and arrow. In the early 1820s, Father Altimira began building California's twenty-first mission with Native American labor, and it became the last mission built in California. After 1834, the Mexican government shifted its focus to developing Sonoma as a pueblo and military outpost and sent General Vallejo from San Francisco to oversee and defend it. Under Vallejo's leadership, Native Americans and others built many adobe buildings, including Casa Grande, his two-story home with a three-story tower, one of the finest homes in California, where many Native Americans worked caring for his children, grooming his horses, and doing other labor. As U.S. settlers arrived from the east, Mexicans in power there were gradually outnumbered, and in 1846 a band of men raised the Bear Flag, captured Casa Grande, took Vallejo prisoner, and declared California an independent republic. Four years later California joined the United States, and Casa Grande later burned in 1867, leaving the Servants' Quarters and the original foundation.