After graduation, he enlisted in the U.S. Army Air Services (U.S. Air Force) at the age of 18 and he was assigned to the Pacific.
In October 1942, Sergeant Bartek and seven others, including Captain Eddie Rickenbacker, crashed into the Pacific Ocean and spent the next 21 days adrift at sea before being rescued. He wrote about his experiences in "My Raft Episode, 21 Days at Sea" and, after the war, lectured about his experiences.
Following his military service, Sergeant Bartek attended photography school and went on to become a photographer for the New Jersey State Police, retiring in 1985.
He was known to be a fan of dancing, big band music, and flower photography.
Sergeant John Francis Bartek died on September 9, 2013, and rests in the Greenwood Cemetery in Hamilton New Jersey.