[1] Upon graduation from the United States Military Academy in 1954, he was commissioned a second lieutenant of armor and awarded a Bachelor of Science degree.

Other key assignments included commanding general of the United States Army Armor Center, commandant, United States Army Armor School, Fort Knox, Kentucky, and assistant deputy chief of staff for operations and plans (force development), HQDA, Washington, D.C., From 31 July 1984, until assuming command of AMC, Wagner served as deputy chief of staff for research, development and acquisition, Department of the Army, Washington, D.C. Wagner served in a variety of progressive assignments preparatory to becoming the commander of AMC.

These included his initial assignment as platoon leader, company executive officer, company commander and assistant S-4, 11th Airborne Division (later reorganized and reflagged as the 24th Infantry Division; separate lineage), Fort Campbell, Kentucky and United States Army Europe, followed by assignment as a troop commander in the 6th Armored Cavalry Regiment, Fort Knox, Kentucky.

After attending the Naval War College, he returned to Vietnam as an infantry and armor advisor.

After promotion to general officer, he was assigned as the deputy director, combat support systems, Office of the Deputy Chief of Staff (Research, Development and Acquisition), United States Army, Washington, D.C. During his army career, Wagner received the following awards and decorations: Distinguished Service Cross, two awards of the Army Distinguished Service Medal, Silver Star, two awards of the Legion of Merit, Bronze Star Medal, Purple Heart, Meritorious Service Medal, two awards of the Air Medal, three awards of the Army Commendation Medal, Combat Infantryman Badge, Senior Parachutist Badge, Ranger Tab, and various foreign decorations.