Walter Brown Gibson was born on September 12, 1897, in Germantown, Pennsylvania, the son of Alfred Cornelius Gibson and May Whidden Gibson. His father was a manufacturer of gas fixtures. The name Maxwell Grant, under which Gibson created the Shadow writings, was derived from the names of two magic dealers whom he knew. Attracted to magic from childhood, Gibson published stories and puzzles at an early age. Former President William Howard Taft praised a story for which Gibson won a literary prize, predicting that he would have a long literary career.
On being graduated from Colgate University in 1920, Gibson went to work for a Philadelphia newspaper. As a reporter, he learned to write quickly and succinctly. At the Philadelphia Evening Ledger, he created the first of many features for their syndicate, “After Dinner Tricks.” Collaborating with noted stage magicians, Gibson produced books under their names, linking his name with those of Harry Houdini, Howard Thurston, and Harry Blackstone. His journalism and editorial experience (for Macfadden magazines) attracted publishers Street and Smith, who needed someone to write a new magazine, The Shadow, which they were planning. Eventually, Gibson would supply twenty-four novelettes each year.
Between 1931 and 1949, Gibson wrote 283 novelettes about the Shadow, one series about magician-detective Norgil, scripts for Super-Magician Comics and Shadow Comics, and several standard magic texts. After six years, a substitute writer was hired to supply additional Shadow material, but Gibson was the major contributor. When the magazine ceased publication, Gibson continued his career with articles for the true-crime magazines, a series of self-help books, new magic books, revisions of some of his earlier titles, comic books and newspaper strips, juvenile titles, and two novels about magician-detectives. On August 27, 1949, he married Pearl Litzka Raymond. Not the first marriage for either of them, it proved a lasting and significant collaboration. A professional magician, Litzka Gibson brought a stability and support to the somewhat nomadic life of her new husband. The majority of his books were published after their marriage. In his later years, Gibson lectured on magic and the Shadow, accepted two awards from the Academy of Magical Arts, and kept in contact with friends around the country. He died on December 6, 1985, in Kingston, New York.