John Paul Denneen was born in Fort Covington, New York, on January 15, 1895, son of Edward J. and Helen M. (Brannen) Denneen, both now deceased. He had his pre-medical training at Canisius College, Buffalo, New York, and in 1919 received the degree of Doctor of Medicine from the University of Buffalo. He served his internship from July 1919 until May 1922, at the New York Postgraduate Hospital, New York, New York, and later at the Sloano Hospital, also in New York City, and subsequently practiced medicine as a Surgeon, in Buffalo, New York. During the period 1937-1938, he attended special courses in surgery in Paris, Vienna, Berlin and Budapest.
Commissioned Lieutenant Commander in the Medical Corps of the United States Naval Reserve on July 25, 1935, he formed the Naval Medical Specialist Unit in West New York that year. Advancing progressively in rank he subsequently attained the rank of Captain, to date from March 10, 1945. On October 4, 1946 he transferred from the Medical Corps of the US Naval Reserve to the Medical Corps of the US Navy, and in February 1, 1957, was retired and advanced to the rank of Rear Admiral on the basis of a combat award
Called to active duty in January 1942, he reported as Chief of Surgery with Unit A at the Naval Operating Base, Norfolk, Virginia. He remained there until December of that year, when he joined USS Leonard Wood to serve as Division Medical Officer of an Amphibious Division and later Staff Surgeon on the staff of Commander Transport Squadron ELEVEN. Continuing duty with Transport Squadron Eleven, he served for six months in USS Fremont, January-July 1945, and finally in USS Cambria. He was awarded the Legion of Merit with Combat “V,” and is entitled to the Ribbon for, and a facsimile of the Navy Unit Commendation awarded the USS Leonard Wood. The citations follow in part:
Legion of Merit: “For exceptionally meritorious conduct…as Staff Surgeon for Commander Transport Squadron ELEVEN in action against enemy Japanese forces during assaults on Makin, Kwajalein, Eniwetok, Saipan, Angaur, Leyte, Lingayen Gulf and Iwo Jima, from November 1943 to March 1945. Skillfully administering and maintaining an exceptionally high degree of coordination and efficiency in the Medical Departments under his command, Captain (then Commander) Denneen capably supervised the evacuation and treatment of numerous casualties, thereby contributing immeasurably to the saving of many lives…”
Navy Unit Commendation: “For exceptionally meritorious service in action against enemy aircraft, shore batteries, mines and submarines…”
In September 1945 he became Senior Medical Officer at Midway Islands and in December 1946 returned to the United States for duty as Chief of Surgery at the Naval Hospital, Norfolk, Virginia. Between March 1947 and February 1949 he was Senior Medical Officer at the Naval Mine Depot, Yorktown, Virginia, with collateral duty as Senior Medical Officer at the Naval Supply Depot, Cheatham Annex, Williamsburg, Virginia, and the Naval Mine Warfare School, Yorktown Virginia. Following an assignment as Assistant Senior Medical Officer at the Marine Corps Schools, Quantico, Virginia, he reported in January 1950 as Senior Medical Officer at the Naval Station, Green Cove Springs, Florida, with additional duty as Medical Officer on the staff of the Commander Florida Group, Atlantic Reserve Fleet
He was Force Medical Officer on the staff of Commander Service Force, US Atlantic Fleet, with additional duty as Atlantic Fleet VD and Epidemiological Medical Officer between January 1952 and September 1955. He then reported as Medical Officer at the Naval Station Dispensary, Key West, Florida. He continued to serve in that capacity until relieved of all active duty pending his retirement, effective February 1, 1957.
In addition to the Legion of Merit with Combat “V,” and the Navy Unit Commendation Ribbon, Rear Admiral Denneen has the Victory Medal (World War I); the American Campaign Medal; the European-African-Middle Eastern Campaign Medal, with insignia; the Asiatic-Pacific Campaign Medal, with one silver star and three bronze stars (eight operations): the World War II Victory Medal; the National Defense Service Medal; and the Philippine Liberation Ribbon, with two stars. He also has the Naval Reserve Medal.
He died February 9, 1964.