The Adventures of Sam Spade was first heard on ABC July 12, 1946, as a Friday-night summer series. The show clicked at once, and went into a regular fall lineup on CBS September 29, 1946. From then until 1949, Sam Spade was a Sunday-night thriller for Wildroot Cream Oil, starring Howard Duff in the title role. With Duff's departure, NBC took the series, leaving it on Sunday for Wildroot and starring Stephen Dunne as Spade. This version lasted until 1951, the last year running as a Friday sustainer.