Start of Mexican-American War and Bear Flag Revolt The United States
declared war on Mexico on May 13, 1846. After receiving word of the declaration of war, a force consisting mostly of American settlers in California staged a revolt on June 15, 1846 against Mexican authorities, which became known at the
Bear Flag Revolt. They overwhelmed and captured the small Mexican garrison at Sonoma and declared the
California Republic (Spanish:
La República de California), or Bear Flag Republic, raising the original
Bear State flag over the captured garrison. Their control was largely restricted to the area around
Sonoma, California and lasted for 25 days. On July 5, 1846, Brevet Captain
John C. Frémont assumed control of the republic's forces and integrated them into his California Battalion. Fremont and his soldiers had not participated in the revolt, though he had given his tacit approval for it. On July 9, 1846, Navy Lieutenant
Joseph Warren Revere arrived in Sonoma and replaced the Bear Flag with the flag of the United States, formally declaring the United States possession of California.
End of Mexican-American War The
Mexican–American War ended with the signing of the
Treaty of Guadalupe Hidalgo in 1848. In the treaty, Mexico
ceded a large portion of northern Mexico in what is now the southwestern United States. With the acquisition of the
large territory, Congress began debating how to organize it. Initially, there was no cause to rush the organization, as the territory was sparsely populated. However, with the
discovery of gold at
Sutter's Mill, California, a large migration of Americans began, as well as an influx of new immigrants from Europe and Asia seeking to find gold or provide goods and services to those seeking gold. The migration gave rise to the immediate necessity of organizing the territory to provide services such as recording land deeds and claims, providing court services and law enforcement, and organizing local governments. ==Admission debate==