John Cassidy was born in June 1915 in Bridgeport, Connecticut, the son of a 17 year old girl who couldn't support a child, so his earliest years were spent in a Slovak nunnery where a maternal aunt served as mother superior. His adolescence was spent in the home of a paternal aunt until he rejoined his mother, on and off, during his high school years. After graduation, Cassidy worked for the Consolidated Gas Company for two years, then went to college in Alabama. He worked as a tree surgeon for the WPA [Annotator's Note: Works Progress Administration, later the Work Projects Administration, was an American New Deal agency created by President Franklin Delano Roosevelt that carried out public works projects including the construction of public buildings and roads] on the campus and attended classes part time.

John Cassidy majored in mining engineering during his first year at the University of Alabama, but he eventually graduated from the education department with a minor in mathematics in 1939. He had applied for Navy officers' training, but nothing came through while he was in college. Cassidy needed money, so he agreed to take a teaching job, but when war seemed eminent, the Navy notified him that there was a position for him. He initially attended school in New York, but switched to Chicago and was eventually commissioned as an ensign in the Navy Reserve. He was out of school a year, working as an ensign on a cruiser, the USS Vincennes (CA-44), essentially preparing for war when Pearl Harbor was attacked by the Japanese. His ship was in dry dock in Boston, and although he expected the confrontation with Japan, Cassidy said he was shocked by the news. Cassidy remembers being called back to his ship, sailing through the Panama Canal, and proceeding to Pearl Harbor, which was all bombed out and looked "like Hell."

Pearl Harbor was "a mess," and John Cassidy said he learned that one of his classmates from officers' candidate school was aboard the USS Arizona (BB-39) which was sunk during the Japanese attack. That sailor's remains are in its hull to this day. Cassidy felt the memorial service that took place at the time was 'half-assed," considering it was the tribute to someone he had loved. There was a gun salute while one casket was lowered into the ground, and the whole ceremony seemed hurried along because of the fear of another attack by what the sailors referred to as "those sneaky bastards." Cassidy said he was bitter for a long time, and when he periodically revisits his friend's burial site in Hawaii, he gets "pissed off again."

After the clean-up of Pearl Harbor, John Cassidy chose to stay in the Pacific on the USS Vincennes (CA-44) which patrolled the larger islands around Midway. Initially, he was in the gunnery department, manning the director, an instrument that maneuvered the guns. Cassidy recalls that the patrols were very boring, like looking for a needle in a haystack, and finding nothing. But those were the orders. Midway was the jumping off spot for further assignment, and Cassidy said his ship was guarding the area so the big ships could come in. His ship sank a "little collection" of submarines, and he remembers being hit by a Japanese torpedo while patrolling one night. The Vincennes was being attacked by Japanese bombers called "Betties" [Annotator's Note: Japanese Mitsubishi G4M medium bomber, known by American servicemen as the "Betty"], and Cassidy was stationed amidships when a faulty torpedo bumped the ship near his position, but failed to explode. He considers himself lucky that the shell just bounced off. Many of the aerial bombs fell just short of the ship. There were other close calls, Cassidy remembers, one when a Kamikaze hit the Vincennes. At the time, he was the admiral's aide, and his job was to keep the admiral, a man who took a lot of chances, safe. There were many fighters in the air, and two of them headed for the ship. When the admiral wouldn't respond to Cassidy's pleas to take cover, he tackled the admiral to the ground and pulled him across the ship, away from where one of the attackers hit the ship at the waterline. Asked what he thought of the Kamikazes, Cassidy said he wondered if the pilots of those planes were "nuts," giving themselves up to get one ship. He said there was a prevalent rumor from a good source that a Japanese pilot had been found chained in his cockpit so he wouldn't abandon the job.

Other close calls John Cassidy remembers included a night when two bombers flew so low, in diversionary tactics while their buddies dropped aerial torpedoes on them, that he could have reached up and touched their planes. Another time, his ship fired a torpedo that malfunctioned and turned back; the crew had to man the guns and shot their own torpedo. Cassidy said "some crazy things happened." Rescuing downed pilots was among the jobs the destroyers performed, and he said the ship picked up George Bush when he ditched on takeoff from an aircraft carrier. Cassidy called the missions the "Crash and Splash Club." Among the moments in the Pacific that stand out to him was "beaning the island girls" that would swim out to the ship. As a bachelor, Cassidy said he saw some cute ones. He was on the USS Vincennes (CA-44) for two years, but had been transferred twice, to the USS Philadelphia (CL-41) and the USS Savannah (CL-42), before the Vincennes was sunk in battle. Cassidy thought staff duty was a lousy job: having to obey what the admiral said even if you disagreed with him, and, he noted, sometimes the admirals had some dumb ideas.

John Cassidy recalled a regular day in his division included an early rise, a shower, breakfast and "quarters" which was reporting for duty. At one point, there were 154 sailors down with dysentery. Cassidy said he rarely corresponded with his three girlfriends; he had no intention of being serious during the war. He said he personally didn't think it fair to hold anybody up. Cassidy said there were lots of nice women, some of them working men's jobs, especially in the port cities like San Francisco, and he was a "hound dog." [Annotator's Note: Cassidy chuckles.] It was three years before Cassidy returned to the United States the first time. Afterward, it was a lot shorter time between visits, but never less than a year. Cassidy met his wife at the second World's Fair in 1940, and married her in 1943. He said he "built" the USS Brown (DD-546), keeping tabs on the civilian workers, in Long Beach, California, and his first child was born there. During his service, Cassidy served as aide to two admirals; one wanted him to continue in his service in peacetime Pearl Harbor, but Cassidy opted to return to his wife and baby.

Returning to the Pacific on the USS Brown (DD-546), John Cassidy participated in the invasion of Okinawa. He was there for more than three months, safeguarding the troops with perimeter patrols. The ships would stand in semi-circular formation, and fight aircraft that were trying to sink the ships. It was dangerous work, and Cassidy had occasion to believe he would not live through the bombing raids, especially the Kamikaze attacks. The water he operated in was infested with sharks which added to the terror. Cassidy said that although he was a great swimmer, he never went in the water, and would advise his own men against taking chances. He said the Japanese attacked every night, and the closer the Allies got to Japan, the fiercer the fighting became. It was important to have good gunners and to know how to use them. Once his ship was hit and had to go into dry dock for repairs to a hole in the hull. Every 13 months destroyers had to go to Guantanamo for training, and during one of the sessions Cassidy had to ride in the plane that towed the targets. He was terrified, but learned the importance of marksmanship, and relayed the message to his crew.

When Japan surrendered, John Cassidy was in the Pacific off Wake Island. He thought the atomic bomb was kind of awesome, and although he didn't agree with wiping out all of Japan, he felt it was out of his "jurisdiction." He says he was on the USS Missouri (BB-63), the surrender ship, as an admiral's aide when the surrender was signed. Cassidy said he felt nothing special being there, and afterward accompanied his admiral on a trip to the East Coast for his transfer. After the war ended, his ship went immediately from Wake Island to Pearl Harbor. It was a long 3,000 mile trip with a shipload of young men who were drafted into service and were anxious to go home. Cassidy moved into the regular Navy, and because he hadn't seen his wife in over a year, and had never seen his son, he refused the opportunity to follow his admiral to Washington, which he said he later regretted.

John Cassidy served as an aide to an admiral during his tenure in the Pacific, and the two men got along well. Cassidy was with him when the admiral learned that his son, a Marine, was injured while storming the beach at Okinawa and had been brought to a MASH unit {Annotator's Note: Mobile Army Surgical Hospital]. There were bullets flying all around the MASH unit, but the admiral was determined to see his son. Cassidy had to muster a crew of volunteers to man a boat and escort the admiral ashore while under fire. The admiral got what he wanted and told Cassidy that he would keep him as his aide for the rest of his career. Instead, when the war ended, Cassidy chose shore duty, and became a Naval ROTC [Annotator's Note: Reserve Officer Training Corps] instructor at Harvard University. After 17 months, he got orders for a staff position in Halifax, Virginia as a senior NATO [Annotator's Note: North Atlantic Treaty Organization, an intergovernmental military alliance between 29 North American and European countries] officer, which Cassidy said was, more than anything, a political job. Afterward, he took command of the USS Coolbaugh (DE-217), and went to sea again. Cassidy remembers that as captain he enjoyed some autonomy, and on one occasion he allowed the sailors' parents to board the ship to see what their sons were doing. His final Navy job was at NASA [Annotator's Note: National Aeronautics and Space Administration], as the supervisor of technical training for the Apollo missions, numbers one through 13. Cassidy was "damn proud" of his work with the space industry. He said he would have enjoyed "a ride to the moon." He was at NASA for 27 and a half months, and the job got "boring," so he retired. He continued working, however, teaching math in Prince William County.

Reflecting on his most outstanding memory of World War 2, John Cassidy said it was surviving the Kamikaze attacks in one piece. He said the experience was, "scary, really scary." Asked how the war changed his life, he said it upset the routine of his family, and his wife didn't appreciate his leaving her. Cassidy said he couldn't answer honestly whether or not he had any lasting psychological effects from the war; but knows that when he left the Navy in 1965, he didn't know what to do for the rest of his life. He is very proud of his service during the war, and feels that the kids today don't care about what it took to earn the freedoms they enjoy today. He feels the work of The National WWII Museum is important, and thinks that young people need to understand what their fore-bearers went through during the war years.