Originally Esposito dreamed of becoming an animator at Disney. This ended when his father did not want him to leave New York for the West Coast. Drafted into the U.S. Army on September 15, 1945, before finishing high school, he served at Camp Dix and Camp Crowder until it was discovered he could draw; Esposito was then dispatched to Germany, where he did venereal disease prevention posters, including the well-known "If you're drippin', you ain't shippin'" and "VD or not VD, that is the question." He was discharged from the Army "in about '47." That year he and Andru both enrolled in Burne Hogarth's Cartoonists and Illustrators School, later renamed the School of Visual Arts. Esposito's first published work in the comic-book field was for Victor Fox's Fox Feature Syndicate, where he worked as penciler, inker, and sometimes letterer.