John Napoleon enlisted in the New York National Guard in 1940, to escape life as a Depression era farmer in Rochester, New York. He enlisted for a period of one year, and following Pearl Harbor he elected to not renew his enlistment in the Guard and then enlisted in the regular army where he was assigned to the newly formed 6th Armored
Division and the 50th Armored Infantry Battalion. He participated in both the VIII Louisiana maneuvers and #1 California maneuvers with the division in 1942. The unit departed for Europe in February 1944, and on 19 June 1944 Mr. Napoleon and the division went ashore on Utah beach to take part in the Normandy campaign. Mr. Napoleon recalled coming ashore on Utah and seeing destroyed jeeps and armored vehicles piled on the beach which left a lasting impression about the fighting in France. When
he had his baptism of fire Mr. Napoleon recalled how he learned to move the .30 cal machine gun he carried to different positions and avoid taking fire, the opposite of what he had been taught to do in training.
Mr. Napoleon's service in France was short lived however, because while moving in a column on a road somewhere in France, the 2 Jeeps at the head of the column were hit by a German Anti-Tank gun, and a platoon of infantry successfully knocked out the gun. A tank was moved to the front of the column, and they were once again fired on by a second Anti-Tank gun, this time Mr. Napoleon's platoon was tasked with knocking out the AT gun. Mr. Napoleon's assistant gunner went ahead of him to select targets for the machine gun, and drew no fire, but while deploying the gun Mr. Napoleon and his assistant gunner were fired on by mortars and small arms and Mr. Napoleon was hit in the leg by rifle fire. After hearing cries from his assistant gunner Mr. Napoleon attempted to rise and render aid, when he was hit by shrapnel from a mortar round and knocked unconscious. When he awoke he was being treated by two medics and was bleeding from his wounds and also his mouth, nose, and ears.