Betty Ballantine

After moving to New York, the couple first ran the Penguin U.S.A. operation. As a team, the Ballantines were involved in the formation of Bantam Books in 1945. Ian became the president from 1945 to 1952 when the pair left to form Ballantine Books.

The new publishing house operated with a new business concept, producing original fiction and publishing both hardbound and paperbound copies at the same time. Some originals included Fahrenheit 451 and A Clockwork Orange. They also published reprints. During the 1960s, they published the first authorized paperback edition of J. R. R. Tolkien's books. Betty Ballantine worked on the editorial part of the business. Along with Frederik Pohl, she searched for science fiction writers in magazines and encouraged them to write novels for Ballantine Books. Irwyn Applebaum, former president of Bantam Dell Publishing Group, said “...much of the editorial vision and brilliance, from variety to quality, that Bantam and Ballantine were known for were due to Betty. Ian was the proselytizer for their brand of books, but Betty was the identifier, the nurturer, the editor.” She was also the force behind The Ballantine Adult Fantasy Series, the first paperbacks in the fantasy genre to be directed toward adults. Authors in this series included Lord Dunsany, H.P. Lovecraft, and Clark Ashton Smith.

They sold the business in 1974 to Random House.