He attempted to join the Spanish Republicans to fight Franco, and later applied to the Royal Canadian Air Force, being turned down on both occasions because of his chronic duodenal ulcer.
[citation needed] However, the Navy apparently decided that he would be better employed with his hand wrapped around a pen rather than around a joystick: he was soon learning, then applying the art of "speed drawing", under the command of the photographer Edward Steichen in a special information unit in which pilot training manuals were produced.
Osborn began drawing cartoons of a pilot who was hapless, arrogant, ignorant and perpetually blundering in ways that put himself and his crew at unnecessary risk.
[11] Osborn illustrated an estimated 2,000 educational posters for Navy pilots between 1942 and the end of the war,[12] some of which appeared in the New York Times and Life magazine.
"[16] Osborn later produced political cartoons, ridiculing Senator Joseph McCarthy,[11] and a number of presidents, from Lyndon Baines Johnson through Ronald Reagan.
"[11] Robert Motherwell wrote that his drawings were "so alive that they seemed to writhe on the page with an uninhibited energy .... Osborn's art is a call to responsible action.
[20] He died of bone cancer, and was survived by two sons, Nic, a naturalist and photographer, and Eliot, a musician and teacher, both of Taconic, Connecticut.