He served in Vietnam as a staff sergeant with Company B of the 2nd Battalion, 12th Cavalry Regiment, 1st Cavalry Division (Airmobile). On the morning of May 18, 1966, Company B was manning a defensive position when they were attacked by a reinforced North Vietnamese company, with the main thrust of the assault pitting Stewart's 6-man squad against a platoon-sized hostile force.
During his service in Vietnam as a staff sergeant with Company B of the 2nd Battalion, 12th Cavalry Regiment, 1st Cavalry Division (Airmobile), on May 18, 1966, Company B was guarding a defensive position when they were attacked by a reinforced North Vietnamese company. The main assault involved Stewart's 6-man squad against a platoon-sized hostile force.