In 1948, Gunn wrote his first science fiction, ten short stories, and published nine from 1949 to 1952 as "Edwin James", a pseudonym derived from his full name James Edwin Gunn. The first two in print, "Communication" and "Paradox" (the first sale), were published in September and October 1949 by editor Sam Merwin in "Startling Stories" and "Thrilling Wonder Stories". Gunn's master's thesis, a critical analysis of the genre, was also published in a professional magazine. His novels were first published by Gnome Press in 1955, "Star Bridge", written by Gunn and Jack Williamson, and "This Fortress World".