In 1853, President Franklin Pierce sent James Gadsden to Mexico City to negotiate with Santa Anna, and the United States bought the remaining southern strip area of Arizona and New Mexico in the Gadsden Purchase. A treaty was signed in Mexico in December 1853, and then, with modifications, approved by the US Senate in June 1854, setting the southern boundary of Arizona and of New Mexico. Before 1846 the Apache raiders expelled most Mexican ranchers. One result was that large herds of wild cattle roamed southeastern Arizona. By 1850, the herds were gone, killed by Apaches, American sportsmen, contract hunting for the towns of Fronteras and Santa Cruz, and roundups to sell to hungry Mexican War soldiers, and forty-niners en route to California. Civil War During the Civil War, on March 16, 1861, citizens in southern New Mexico Territory around Mesilla (now in New Mexico) and Tucson invited take-over by the Confederacy. They especially wanted restoration of mail service. These secessionists hoped that a Confederate Territory of Arizona (CSA) would take control, but in March 1862, Union troops from California captured the Confederate Territory of Arizona and returned it to the New Mexico Territory. The Battle of Picacho Pass, April 15, 1862, was a battle of the Civil War fought in the CSA and one of many battles to occur in Arizona during the war among three sides—Apaches, Confederates and Union forces. In 1863, the U.S. split up New Mexico along a north–south line to create the Arizona Territory. The first government officials to arrive established the territory capital in Prescott in 1864. The capital was later moved to Tucson, back to Prescott, and then to its final location in Phoenix in a series of controversial moves as different regions of the territory gained and lost political influence with the growth and development of the territory. Native American relations In the late 19th century the Army built a series of forts to encourage the Natives to stay in their territory and to act as a buffer from the settlers. The first was Fort Defiance. It was established on September 18, 1851, by Col. Edwin V. Sumner to create a military presence in Diné bikéyah (Navajo territory). Sumner broke up the fort at Santa Fe for this purpose, creating the first military post in what is now Arizona. He left Major Electus Backus in charge. Small skirmishes were common between raiding