John Spade was an American who worked for the Pinkerton National Detective Agency. He grew up in San Francisco, the son of a policeman named Samuel Spade and his wife Faith Shawnessy. John married a French-Canadian woman named Edwina Land; their son Sam Spade became a celebrated San Francisco private eye.
The Spade family are discussed by Philip José Farmer in his book Doc Savage: His Apocalyptic Life.