World War II Medal of Honor Recipient. A US Navy ace fighter pilot, he received the award from President Franklin D. Roosevelt at the White House on April 21, 1942, for his actions as a lieutenant assigned to the US Navy aircraft carrier USS Lexington on February 20, 1942, in the South Pacific, The son of a prominent Chicago, Illinois attorney, following high school he received an appointment to the US Naval Academy at Annapolis, Maryland and was commissioned an ensign in June 1937. He served the nest two years on the battleship USS New Mexico and in 1939 he began flight training at the US Naval Air Station in Pensacola, Florida, After completing his naval aviation training in May 1940, he was assigned to Fighter Squadron Three (VF-3) on board the aircraft carrier USS Saratoga in the Pacific. Shortly after the US entered World War II, the Saratoga was damaged by a Japanese torpedo and his squadron was reassigned to the aircraft carrier USS Lexington. It was a month later that he became engaged in battle with Japanese fighters off of the coast of Bougainville, Papua New Guinea for which he was awarded the Medal of Honor, thereby becoming America's first World War II ace. He returned to the US a hero and spent the next year campaigning in war bond tours and other publicity initiatives. In August 1943 he returned to duty in the Pacific, flying F6F-3 Hellcat fighters aboard the aircraft carrier USS Independence and saw action at Marcus Island and Wake Island. In September 1943, he became the Commander Air Group Six on the aircraft carrier USS Enterprise. On November 26, 1943 he participated in an experimental nighttime mission near the Pacific's Gilbert Islands and during the course of the mission, his aircraft was caught in an apparent crossfire and crashed into the ocean. His body was never recovered. He was also awarded the Navy Cross, the Distinguished Flying Cross (with one gold star) and the Purple Heart. His citation reads "For conspicuous gallantry and intrepidity in aerial combat, at grave risk of his life above and beyond the call of duty, as section leader and pilot of Fighting Squadron 3 on 20 February 1942. Having lost the assistance of his teammates, Lt. O'Hare interposed his plane between his ship and an advancing enemy formation of 9 attacking twin-engine heavy bombers. Without hesitation, alone and unaided, he repeatedly attacked this enemy formation, at close range in the face of intense combined machinegun and cannon fire. Despite this concentrated opposition, Lt. O'Hare, by his gallant and courageous action, his extremely skillful marksmanship in making the most of every shot of his limited amount of ammunition, shot down 5 enemy bombers and severely damaged a sixth before they reached the bomb release point. As a result of his gallant action--one of the most daring, if not the most daring, single action in the history of combat aviation--he undoubtedly saved his carrier from serious damage." The first United States Navy ace, he was downed by a Japanese "Betty" bomber flying slightly above and behind him, in position to see his engine exhaust flames, and his body was lost at sea. In 1945 the US Navy launched the destroyer "USS O'Hare" (DD-889), which was named in his honor. O'Hare International Airport in Chicago, Illinois was named in his honor.