Chisum became one of the major stock men in North Central Texas before the Civil War. During the War, he supplied cattle to the Confederacy. He became associated with Charles Goodnight before moving to New Mexico where he created a vast ranch which in 1875 employed 100 cowboys and ran 80,000 head of cattle. He was a key figure of the Lincoln County War (1878-1881) when large ranchers fought against small cattlemen and farmers. The movie Chisum, staring John Wayne, was based upon his life as a cattleman.