Hickman's professional career was launched in 1972 when he got a job creating T-shirt designs for Shirt Explosion in Lanham, Maryland. Hickman was given virtually unlimited artistic freedom. His entry into book illustration came in 1974, when Neal Adams of Continuity Studios introduced Hickman to Charles Volpe, art editor at Ace Books. Volpe bought the printing rights of items from Hickman's portfolio, and later commissioned paintings which were used for reprints of Ace Doubles in the Classics of Science-Fiction series. Hickman then became a full-time artist.[1] His most prominent work is Space Fantasy Stamps, a series of science fiction and fantasy postage stamps made for the United States Postal Service.[1] These stamps are a series of five scenes that depict space travel.[2]
