Carson came to realize that the hostilities between white Americans and Native Americans were the result of a great decrease in available wild game. This situation forced the Native Americans into raiding American farms, ranches, and herds of cattle. He also knew that the liquor available in towns and villages led the Native Americans into serious trouble. Carson wanted the government to put aside large areas of land far from white settlements. The lands would be called reservations, and were intended for the use of Native Americans only. He thought the Native Americans should be taught agriculture, but it would prove almost impossible to teach nomadic hunters to settle on one piece of land and farm it. He thought his plans would keep these peoples from becoming extinct. Carson resigned as Indian agent with the outbreak of the American Civil War in April 1861. He joined the Union Army to lead the 1st New Mexico Volunteer Infantry.