Amos Chapman, frontiersman, was born on March 15, 1837, of mixed White and Indian parentage in Michigan. Beginning in the late 1860s, he served as a civilian scout and interpreter for the United States Army and was often hired as a guide for settlers moving to Kansas and Colorado. In September 1868 he scouted for Maj. Joel H. Elliott's Seventh Cavalry detachment during Gen. Alfred Sully's campaign against the Southern Cheyennes from Fort Dodge, Kansas. That campaign led to the establishment of Camp Supply in Indian Territory, where Chapman subsequently served as an interpreter. There he married Mary Longneck, a daughter of the Cheyenne chief Stone Calf, and lived for a time among her tribe. They had six children. During the early 1870s he was involved in the army's attempts to keep whiskey peddlers and outlaws out of the reservations.
Chapman volunteered his services to Col. Nelson A. Miles's regiment in July 1874 and scouted for Lt. Frank D. Baldwin. While carrying dispatches for Miles on September 12, Chapman, William (Billy) Dixon, and four troopers ran into a party of more than 100 Comanches and Kiowas near Gageby Creek, in what is now Hemphill County. In the resultant Buffalo Wallow Fight, Chapman's left knee was shattered by a bullet while he was attempting to aid the fatally wounded George Smith. He managed to hold out until Dixon was able to reach him and carry him to the safety of the wallow. Subsequently, Chapman's injured leg was amputated by the post surgeon at Camp Supply. For their heroism he and his comrades were awarded the Medal of Honor, but the award was later revoked for Chapman and Dixon because they were civilians. In 1989 their medals were restored by the army.
After the Red River War Chapman, who thereafter wore an artificial leg, continued in his role as post interpreter. He worked vigorously on behalf of his wife's people and helped keep order during the excitement surrounding Dull Knife's flight in 1879. When James Monroe (Doc) Day and other free-range cattlemen began running their herds on reservation lands, Chapman again wielded his influence to prevent bloodshed. He helped work out peaceful solutions, which included designating certain routes, such as the Deep Creek Trail, over which cattle could graze and be driven to the Kansas markets. After his retirement from government service, Chapman and his wife settled on a ranch four miles east of Seiling, Oklahoma. It was said that they "divided matters evenly." Sometimes they slept in a tepee, for instance. Chapman died on July 18, 1925, from injuries sustained in an accident with his spring wagon. At the time, he was preparing to lecture on his frontier days with a lyceum circuit. He was buried at Seiling.