geronimo

In 1940, the night before their first mass jump, U.S. paratroopers at Fort Benning
watched the 1939 film Geronimo, in which the actor playing Geronimo yells his
name as he leaps from a high cliff into a river, depicting a real-life escape Geronimo
successfully attempted in which he jumped off Medicine Bluff at Fort Sill, Oklahoma,
into the Medicine Creek with his Cadillac horse. Private Aubrey Eberhardt announced
he would shout the name when he jumped from the airplane to prove he was not
scared. The trend has since caught on elsewhere, becoming widely associated with
any sort of high jump in popular culture.