G.I. is an informal term that refers to "a soldier in the United States armed forces, especially the army".[1] It is mostly deeply associated with World War II, but continues to see use.
It was originally an initialism used in U.S. Army paperwork for items made of galvanized iron.[2] The earliest known instance in writing is from either 1906[3] or 1907.
During World War I, U.S. soldiers took to referring to heavy German artillery shells as "G.I. cans". During the same war, "G.I.", reinterpreted as "government issue" or "general issue", began being used to refer to any item associated with the U.S. Army (e.g. "G.I. soap"). Other reinterpretations of "G.I." include "garrison issue" and "general infantry".
The earliest known recorded instances of "G.I." being used to refer to an American enlisted man as a slang term are from 1935. In the form of "G.I. Joe" it was made better known due to it being taken as the title of a comic strip by Dave Breger in Yank, the Army Weekly, beginning in 1942. A 1944 radio drama, They Call Me Joe, reached a much broader audience. It featured a different individual each week, thereby emphasizing that "G.I. Joe" encompassed U.S. soldiers of all ethnicities.[4] They Call Me Joe reached civilians across the U.S. via the NBC Radio Network and U.S. soldiers via the Armed Forces Radio Network.
"G.I. Jane" originally referred to a member of the Women's Army Corps during World War II but more recently it is used to refer to any American woman soldier.
In British military parlance and in armed forces modelled on British military traditions, G.I. refers to a Gunnery Instructor, generally an NCO responsible for inducting and training recruits.