Robert Keith Leavitt (1895–1967) was a Harvard-educated New York City advertising copywriter who turned to non-fiction writing. He was the author of many books, including a history of Webster's Dictionary and "The Chip on Grandma's Shoulder" (1954.) 'Bob' Leavitt was also the longtime historian of the original The Baker Street Irregulars, devoted to all things Holmesian, about which he wrote in his "The Origins of 221B Worship."[1]