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.
Centralist Republic of Mexico
After Federalism was restored in 1846, Yucatán decided rejoin Mexico, but a considerable minority opposed the reinstatement due to the U.S. invasion of Mexico in the Mexican–American War (1846–48). On 30 July 1847, Yucatán's Maya population rebelled in a conflict now known as the Caste War. The war forced Yucatán to seek help from Mexico, which negotiated their return to the Republic, which took place on 17 August 1848. The conflict in Yucatan was largely contained, with the Yucatecan government declaring victory. However, pockets of resistance continued to exist for another 50 years, when Mexican army troops destroyed the last Maya stronghold.