In his accompanying letter of authentication (copy), noted Colt historian and author John Kopec confirmed that this "revolver no. 10139 is listed in the National Archives records as being issued on June 20, 1898 to a George Thompson of the U.S.V. Cavalry (Rough Riders)." The Rough Riders, officially the 1st U.S. Volunteer Cavalry, are the most famous of all U.S. units from the Spanish-American War and are particularly well-known for being led by future president Theodore Roosevelt during their charge up Kettle Hill during the Battle of San Juan Hill. As noted in the accompanying Springfield Research Service letter, George Thompson was a native of Fairmont, Minnesota, and at age 29 enlisted on June 24, 1898 around the time the first troops of the Rough Riders were engaged in combat in Cuba and was assigned to Troop I on July 8. His civilian occupation was that of a cook. Thompson came down with dysentery and was admitted to a hospital in Jersey City, New Jersey, on August 18. He was discharged from service on September 29, 1898. Kopec theorized that the revolver did not take part in the 1895-1896 Colt factory refurbishment but instead was "taken from storage, its barrel shortened and then re-issued for service from one of the arsenals....After a period of service, it is my opinion that this revolver was then sent to Colt's (possibly during 1903) to again be refurbished. It was during this refurbishing that all of the serial numbers were mixed, and the caliber designation '45 COLT' applied to the old Ainsworth sub-inspected barrel. A later style (early 1900's) hammer was also fitted during this refurbishing." The trigger guard (no. 336) originated from a first year production revolver that Kopec believed saw service with the 6th or 8th Cavalry. The back strap (no. 1294) was also from a first year production revolver that may have saw service with the 6th Cavalry. The cylinder serial number as well as sub-inspector marks are illegible. The Ainsworth sub-inspected barrel (no. 9200) is from a host revolver manufactured in 1874. Kopec noted that the grips appear to be Colt factory in origin "but have no distinguishing external markings" with a faint "9454" serial number in the back strap channel. Kopec noted that the "grips are in remarkable condition." Kopec found "no evidence of fakery or deception on this revolver."