He was born in Madison County, Kentucky. During his career throughout the desert Southwest, he was a trapper, guide, military scout, Indian agent, soldier (rising to the rank of brigadier general), and rancher. His renown initially came from guiding John C. Fremont on an expedition to map the western trails to the Pacific Ocean. Descriptions in Fremont's popular report of his expeditions made Kit Carson famous.
When civil war erupted in April of 1861, Kit Carson resigned his post as federal Indian agent for Northern New Mexico and offered to help organize the New Mexico volunteer infantry. Although the territory of New Mexico officially allowed slavery, geography and economics made the institution so impractical that there were only a handful of slaves within its boundaries. The territorial government and the leaders of opinion all threw their support to the Union.
Overall command of Union forces in the Department of New Mexico fell to Colonel Edward R. S. Canby of the Regular Army's 19th Infantry, headquartered at Fort Defiance. Carson, with the rank of colonel of volunteers, commanded the third of five columns in Canby's force. Carson's command was divided into two battalions each made up of four companies of the First New Mexico Volunteers, in all some 500 men.
Early in 1862, Confederate forces in Texas under General H. H. Sibley undertook an invasion of New Mexico Territory. The goal of this expedition was to conquer the rich Colorado gold fields and thus deprive the Northern war machine of a valuable resource and direct it instead to Southern coffers.
Advancing up the Rio Grande River, Sibley's command clashed with Canby's Union force at Valverde on February 21, 1862. The day-long battle ended when the Confederates captured a Union battery of six guns and forced the rest of Canby's troops back across the river with losses of 68 killed and 160 wounded. Colonel Carson's column spent the morning on the west side of the river out of the action, but at one o'clock, Canby ordered them to cross, and Carson's battalions fought until ordered to retreat. Carson lost one man killed and one wounded.
Colonel Canby had little or no confidence in the hastily recruited, untrained New Mexico volunteers, "who would not obey orders or obeyed them too late to be of any service." However, in his battle report he did commend Carson, among other volunteer officers, for his "zeal and energy." After the battle at Valverde Colonel Canby and most of the regular troops were ordered to the eastern front, but for Carson and his New Mexico Volunteers Indian troubles occupied their full attention.
The new commander of the District of New Mexico, Brigadier-General James H. Carleton, ordered Carson to lead an expedition against the Navajo Indians, who continued to resist the white invasion of their land. The Navajos should be told, Carleton instructed Carson, "You have deceived us too often, and robbed and murdered our people too long, to trust you again at large in your own country. This war shall be pursued against you if it takes years, now that we have begun, until you cease to exist or move. There can be no other talk on the subject."
Colonel Carson pursued the Navajo across much of New Mexico. There were no pitched battles and only a few skirmishes, for Carson's principal tactic was to destroy or capture the Navajos' crops and animals. In this effort he was aided by other Indian tribes, long-standing enemies of the Navajos, chiefly the Utes. Carson was pleased with the work the Utes did for him, but felt some irritation when they went home in the middle of the campaign, having collected what they thought was sufficient booty.
Carson also had difficulty with his New Mexico volunteers. Troopers deserted and officers resigned. Carson urged Carleton to accept two resignations he was forwarding, "as I do not wish to have any officer in my command who is not contented or willing to put up with as much inconvenience and privations for the success of the expedition as I undergo myself."
In 1864, the Navajos surrendered and were marched off to a reservation. General Carleton in October 1865 recommended that Carson be awarded the brevet rank of brigadier-general, "for gallantry in the battle of Valverde, and for distinguished conduct and gallantry in the wars against the Mescalero Apaches and against the Navajo Indians of New Mexico."
When the Civil War ended, and with the Navajo campaign successfully concluded, Carson left the army and took up ranching in Colorado. He died there in 1868, but the legend of Kit Carson continued to grow through the years as dime-novels, comic books, movies and television recounted (and invented) the frontiersman's many exciting adventures.