Paul Detlefsen was born in Copenhagen, Denmark. He was the son of a medical doctor. He studied at the School of the Art Institute of Chicago before moving to Hollywood to build his reputation as a cartoonist. After not succeeding as an animator, he produced backdrops for films. He was nominated at the 17th Academy Awards, along with coworkers John Crouse and Nathan Levinson, for their work on the 1944 film "The Adventures of Mark Twain". The only other films Detlefsen is credited for are "The Horn Blows at Midnight" (1945), "Escape in the Desert" (1945), and "Shadow of a Woman" (1946), but he spent 20 years at Warner Brothers Studios, eventually rising to be in charge of the art department that created matte backdrops.