Politics in Mexico became violent and several Mexican States declared independence. On March 2, 1836, Texas declared independence from Mexico and soon they were at war. Texas won, but Mexico refused to recognize Texas as an independent sovereign Republic. Texas soon requested entry to the United States. Years later, in 1845, the US added Texas as a state, and Mexico broke off diplomatic relations. Mexico resisted offers by the U.S. to buy land extending from Texas to the Pacific Ocean. In 1846, a dispute over the border between Texas and Mexico resulted in armed conflict, and the Mexican-American War began. The United States won the war, and by the Treaty of Guadalupe-Hidalgo, in 1848 won lands that later formed the states of California, Arizona, Nevada, Utah, New Mexico, southwestern Colorado, and southwestern Wyoming. Mexico received 15 million dollars and gave up its claims to Texas.