After participating in the North African Campaign with his unit, Maxwell took part in the Allied invasion of Sicily on July 10, 1943, marching to Palermo, and on to Messina. The 7th Infantry then landed at Salerno in September shortly after the Allied invasion of mainland Italy and fought northwards to an area near Cassino. During the early stages of the subsequent Battle of Anzio in January 1944, Private First Class Maxwell repaired damaged wire lines to maintain communication under intense artillery fire for over three hours on January 31 and was wounded in the leg. For his actions under fire that day, he was awarded the Silver Star. He spent the next few months recovering at a hospital in Naples.