Robert Allen McAllister was born on July 16, 1948, grew up on the family farm in Tinley Park, and was the second of six children born to Ray and Dorothy McAllister. After graduating from Carl Sandburg High School in 1966, he joined the Marines. On August 18, 1968, he was killed in action in Vietnam when his group came under enemy attack. Although mortally wounded as he attempted to reach the battery aid station, he saw two hostile soldiers about to attack a bunker containing several fellow Marines. Despite his injuries, he used his remaining strength to deliver accurate fire against the enemy soldiers and prevented the attack, saving those Marines from death or serious injury. For his actions that day, he was awarded the Silver Star Medal posthumously.