Yuma War
The Yuma War was the name given to a series of United States military operations conducted in southern California and what is today southwestern Arizona from 1850 to 1853. The Yumans were the primary opponent of the United States Army, though engagements were fought between the Americans and other native groups in the region. Conflict generally took the form of guerrilla warfare, and, over the course of three years, the army engaged in pursuing unfriendly natives, protecting American settlers crossing the Colorado River and preventing conflict between the native tribes. A peace treaty in summer of 1853 was signed, ending hostilities between the Yuma and the United States, but it sparked a short war between the Yuma and the Cocopah. During the conflict, the historic Fort Yuma was constructed and became an important outpost on the frontier.
Yuma War
Following the Gadsden Purchase in June 1853, the eastern side of the Colorado became part of the United States and though the war was over between the Yuma and the Americans, the United States Army could now launch major military campaigns across the river without having to concern themselves with the Mexican military. War between the United States and the Mohave became a reality in 1858 when warriors attacked American settlers at Beale's Crossing in Arizona. The attack resulted in the establishment of Fort Mohave and the Mohave War ended in 1859 after the Mohave were defeated twice in two significant engagements.