William served with the Strategic Air Command, United States Air Force. He held a secret clearance working on B-52 bombers, KC-135 refueling aircraft, and Minuteman missiles. William received his Honorable Discharge from the United States Air Force in 1965.
William joined the United States Navy fulfilling a dream previously frustrated by chronic motion sickness. He served aboard the submarine USS Tiru (SS-416), USS Tombigbee (AOG-11), Naval Support Activity Danang RVN, Naval Security and Intelligence Camp Carter RVN, Danang Harbor Patrol RVN, Dong Ha River Security Group RVN, USS Charles Berry (DE-1035), Headquarters Commander in Chief Pacific Fleet, USS Oriskany (CVA-34).
Cooper was a member of the Office of Naval Security and Intelligence serving as a Harbor and River Patrol Boat Captain at Danang and the Dong Ha River Security Group, Cua Viet, Republic of Vietnam. William Cooper was awarded several medals for his leadership and heroism during combat including two with "V" for Valor.
He served on the Intelligence Briefing Team for the Commander In Chief of the Pacific Fleet. William was the Petty Officer of the Watch and designated KL-47 SPECAT operator in the CINCPACFLT Command Center at Makalapa Hawaii. There he held a Top Secret, Q, SI, security clearance.
William Cooper achieved the rank of First Class Petty Officer, QM1, E-6 after only 8 years of Naval service, a difficult task in any branch of the United States military. William Cooper received an Honorable Discharge from the United States Navy on December 11, 1975.