[6] Carpenter served as a Seabee in the U.S. Navy during World War II and helped to build the airstrip from which the Enola Gay took off for its flight to bomb Hiroshima.

[7] Carpenter began his performing career as a magician and an actor on Broadway, beginning with David Merrick's first production, Bright Boy, in 1944, followed by co-starring appearances in Three to Make Ready with Ray Bolger, John Murray Anderson's Almanac, and Hotel Paradiso.

[citation needed] Carpenter was brought to Hollywood in 1949 by independent producer Louis de Rochemont to play the boyfriend in Lost Boundaries.

Carpenter's later stage appearances included Hello, Dolly!, opposite Mary Martin (which toured Vietnam during the war and was filmed as a one-hour NBC-TV special), The Boys in the Band, Dylan, Crazy For You, and the City Center revival of Kander and Ebb's 70, Girls, 70.

Carpenter wrote material for Debbie Reynolds, Kaye Ballard, Marlene Dietrich, and Hermione Gingold, and also scripts for films and television.

His books include Deadhead, Games Murderers Play, Cat Got Your Tongue?, Only Her Hairdresser Knew, Sleight of Deadly Hand, The Peabody Experience, and Stumped.