Born in Durango, Mexico, Ralph O'Neill spent the years of his youth growing up in the Borderlands region of the American southwest and northern Mexico, including Nogales, Arizona. Following a yea of study at Lehigh University and America's entry into the First World War, O'Neill enlisted in the Army Signal Corps in June 1917. Attaining his wings at Everman Field at Ft. Worth, he was commissioned a 2nd Lt. and assigned to the 147th Aero Squadron flying Nieuport 28 & SPAD 1 fighters. In July 1918, O'Neill downed as many as 6 German aircraft and was hailed as one o America's first aces. By the war's end, he had risen to the rank of 1st Lt., officially been credited with victories, flown 103 combat patrols and was thrice decorated for extraordinary heroism, receiving 3 Distinguished Service Crosses & the French Croix de Guerre with Palm.
In 1920, O'Neill was appointed by the Mexican Government to train and organize a modern Mexican air force. Upon hi return to the U.S. in 1925, he conceived the idea of an airline & mail service connecting the east coasts of North & South America utilizing large flying boats. Following a stint in 1927 as the exclusive Latin American agent for both Boeing an Pratt & Whitney, O'Neill founded and headed the New York, Rio & Buenos Aires Line in 1929, piloting much of the maiden flight himself in a Sikorsky S-38. After NYRBA merged with Pan Am in 1930, he formed a gold mining company Bolivia. O'Neill retired to the Bay area in the late 1960's where he lived until his death in 1980.