Colonel Claude E. Clifton was commissioned an Infantry Officer upon graduation from Officer Candidate School 25 February 1966. | His first duty assignment was as a Platoon Leader, Company C, 3d Battalion, 39th Infantry, 9th Infantry Division, Fort Riley, Kansas. | His subsequent duty assignments include: Platoon Leader, Company C, 3d Battalion, 39th Infantry, 9th Infantry Division, Vietnam; Motor Officer, Headquarters and Headquarters Company, 3d Battalion, 39th Infantry, 9th Infantry Division, Vietnam; Company Commander, Company C, 2d Battalion, 10th Infantry, 5th Infantry Division (Mechanized), Fort Carson, Colorado; S-4, 3d Battalion, 10th Infantry, 5th Infantry Division (Mechanized), Fort Carson, Colorado; S-3, 3d Battalion, 10th Infantry, 5th Infantry Division (Mechanized), Fort Carson, Colorado; Company Commander, Headquarters and Headquarters Company, 2d Battalion, 7th Cavalry Battalion, 1st Cavalry Division, Vietnam; Instructor, Unassigned, 20th Student Battalion, Fort Benning, Georgia; Assistant S-3, 3d Advanced Individual Training Brigade, U.S. Army Training Center, Fort Jackson, South Carolina; Assistant S-3, 391st Engineer Battalion, 120th Army Reserve Command; Plans Officer, Deputy Chief of Staff Operations and Intelligence, 120th Army Reserve Command; Operations Officer, Deputy Chief of Staff Operations and Intelligence, 120th Army Reserve Command; Chief, Administrative Officer, Deputy Chief of Staff Operation and Intelligence, 120th Army Reserve Command;  Chief, Plans and Operation Division, Deputy Chief of Staff Operations and Intelligence, 120th Army Reserve Command; Chief, Plans and Intelligence Division, Deputy Chief of Staff Operations and Intelligence, 120th Army Reserve Command; Assistant Deputy Chief of Staff, (Operations and Intelligence), Deputy Chief of Staff Operations and Intelligence, 120th Army Reserve Command; Army Reserve Personnel Center; Director, Plans, Training and Mobilization, Individual Mobilization Augmentee, 101st Airborne Division (Air Assault), Fort Campbell, Kentucky; Assistant Chief of Staff, Plans and Operations, 361st Cavalry Brigade; Deputy Chief of Staff, Operations, 120th Army Reseve Command; and Chief of Staff, 120th Army Reserve Command.