Guy flew biplanes for both France's Aeronautique Militaire and the U.S. Army Air Service during World War I.

[5] Guy's grandfather, David Everett Wade, served in the American Revolutionary War after growing up in Northern New Jersey.

[2] Guy served as an ambulance driver with the American Field Service (AFS) from February to July 1917.

[2] On November 7, 1918, Guy left the Aeronautique Militaire to join the U.S. Army Air Service with the rank of first lieutenant.

After World War I, Guy co-founded the National Aeronautical Association's Flying Club of Philadelphia,[10] and he served as its first president.

[11] Following the end of the war, Guy resumed his college studies at the Massachusetts Institute of Technology in Cambridge, MA.

After working at the First Pennsylvania Banking and Trust Company in Philadelphia, he co-founded Wellington Foundation and served as their president.