Robert McMahon, from New Orleans, completed Basic Training at Camp Walters, Texas, before shipping out for the Pacific theater. He joined the 182nd Infantry Regiment on Bougainville in April 1944, as a replacement for the casualties suffered during the Battle for Hill 260. He was promoted to Private First Class in December, just before the unit headed out for the Philippines. He was wounded in action on 13 April 1945 during the climactic final battle at the top of Babag Ridge on Cebu. During the fighting, he initially suffered a minor gunshot wound to his arm, but continued on. In the darkness at the top of the ridge, as he pushed on up the hill, a Japanese grenade rolled down, exploding nearby and badly wounding his leg. He was evacuated to a nearby field hospital, and then flown out to a hospital on Leyte. He was still on Leyte when news came in that the war was over. He returned home to Louisiana after the war, where he resided until he passed away in 2020.