Major General Samuel A. Leffler was named Platoon Leader of Company A upon graduation of the U.S. Army Signal School in 1962. He served the 142d Signal Battalion, 2d Armored Division, Fort Hood, Texas (1964). Upon completion of classes he served as Commander, 16th Aviation Detachment, 516th Signal Group, U.S. Army Europe, Germany (1967); Signal Officer 223d Combat Support Aviation Battalion, U.S. Army, Vietnam (1968); Executive Officer, 36th Signal Battalion, 1st Signal Brigade, U.S. Army, Vietnam (1970); Commander, 124th Signal Battalion, 4th Infantry Division (Mechanized), Fort Carson, Colorado (1977); He served in numerous positions in the U.S. Army in Washington D.C. (1978 - 87); Commander General/Deputy Chief of Staff for Information management, 5th Signal Command, Germany (1989).

He then served at Washington D.C. from 1991-92. He then finished off his enlistment as the Commanding General, U.S. Army Systems Command, Fort Huachuca, Arizona (1992-95). His U.S. awards include the Legion of Merit (3 Oak Leaf Clusters), Bronze Star Medal with V Device (2 Oak Leaf Clusters), Meritorious Service Medal (One Oak Leaf Cluster), Air medals, Army Commendation Medal, Parachutist Badge, Senior Army Aviator Badge, and Army Staff Identification Badge.

He retired from the Army August 31, 1995.