Following the 1932 Games, Eagan served as assistant U.S. attorney for Southern New York. But soon he was presented with another chance to add to his heroic resume. In 1941, when the U.S. entered World War II, Eagan joined the Army Air Corps, becoming chief of special services in the air-transport command. By the end of the war he had earned the rank of lieutenant colonel.
Eagan returned to civilian life and continued to play a role in American sports development, including stints as head of the New York State Athletic Commission, chairman of President Dwight Eisenhower's People-to-People sports committee (a sort of athletic ambassadorship to the world) and director of the sports program for the 1964 New York World's Fair.
He died of a heart attack in 1967, six weeks after his 69th birthday. Sixteen years later, Eagan was one of the inaugural inductees—along with Jesse Owens, Wilma Rudolph, Mark Spitz and Erie Heiden, among others—into the U.S. Olympic Hall of Fame. Frank Merriwell can't claim that.