Ace Books was founded in New York City in 1952 by Aaron A. Wyn. It began as a genre publisher of mysteries and westerns and soon branched out into other genres, publishing its first science fiction title in 1953. "Ace published historicals, war novels, juvenile delinquent books, and borderline sleaze. They added a line of ‘singles’ and the Ace Star series for larger and more expensive books, but they remained best known for their genre‐oriented Ace Double Books."—Richard A. Lupoff, The Great American Paperback