H. Allen Anderson, “Pratt, Richard Henry,” The Handbook of Texas Online, http://www.tshaonline.org/handbook/online/articles/PP/fpr33.html.
He applied for a commission in the regular army and on March 7, 1867, was appointed second lieutenant in the newly organized Tenth United States Cavalry, composed of black enlisted men with white officers. At Fort Arbuckle, Indian Territory, Pratt was promoted to first lieutenant on July 31. He began his long association with the American Indian when Lt. Col. John W. Davidson, the district commander, placed him in charge of the regiment's Indian scouts. Pratt took part in the Washita campaign of 1868 and over the next several years saw duty at Fort Sill and Camp Supply, as his unit sought to maintain order on the government Indian reservations. In the spring of 1873 he was transferred to Fort Griffin, in Texas, where he was given command of the Tonkawa scouts in addition to his Tenth Cavalry troop. Even as he participated in efforts to curb Comanche and Kiowa depredations and stop the illicit whiskey trade, his interest in and understanding of the Indians deepened. When the Red River War broke out, Pratt and his Tonkawa contingent accompanied Davidson's column into the Texas Panhandle in September and October 1874. In early November he was among those who pursued Grey Beard's scattered Cheyenne warriors for ninety-six miles to the Canadian River in what is now Potter County with Capt. Charles D. Vielé's command before weary mounts and icy weather forced the column back to Fort Sill.