Schaefer joined the Army from Long Island, New York in January 1942, and by September 24, 1944 was serving as a Staff Sergeant in Company I, 18th Infantry Regiment, 1st Infantry Division. On that day, near Stolberg, Germany, Schaefer led his squad in their defense against a German attack. He voluntarily took the most dangerous defensive position, killed many of the attacking soldiers, and single-handedly captured ten.
He then participated in the American counter-attack and freed a group of American soldiers captured earlier.
Schaefer later served in the Korean War. He died at age 68 and was buried at Long Island National Cemetery, Farmingdale, New New York
The Germans attacked again with grenades and flame throwers but were thrown back a second time, Recognizing the threat.