Colonel Donald J. Hassin was commissioned an Infantry Officer upon graduation from Officer Candidate School on 3 May 1943. His first duty assignment was as Training Officer, Training Center, Camp Joseph Robinson, Arkansas. | His subsequent duty assignments include:  Platoon Leader and Staff Officer, 3rd Battalion, 115th Infantry, 29th Div, ETO; Company Commander, Battalion S-3, 13th Armored Infantry Bn, Fort Knox, Kentucky; Assistant S-3, Battalion S-3, 14th Infantry, 25th Div, Korea; Assistant PMississippiF, Augusta Military Academy,  Virginia; Infantry Advisor, Military Assistance Group, Bonn, Germany; S-3, Special Troops Eighth Army, Korea; Assistant Secretary General Staff, Office Chief of Staff, Pentagon; Battalion Commander, 4th Bn, 18th Infantry, Berlin, Germany; Brigade Commander, 4d-l Brigade (Training), Fort Knox, Kentucky. | Military schools attended include:  Command and General Staff College, USAREUR Intelligence School, German Language, The Infantry School IOAC. | His awards and decorations include: Legion of Merit, Meritorious Service Medal, Bronze Star w/ V Device and One Oak Leaf Cluster, Army Commendation Medal w/ Three Oak Clusters, Purple Heart, Combat Infantryman Badge w/ Star, European Service Ribbon w/ Four Campaign Stars, Korean Service Ribbon w/ Two Campaign Stars, General Staff Badge.