Matthew Josephson was an American historian, biographer and journalist. He authored works on French novelists of the 19th century, and on U.S. political and economic history of the 19th and early 20th centuries. He popularized the term "robber baron" in his best-selling 1934 book The Robber Barons about the first American tycoons. No. 1 on The New York Times Nonfiction best seller list for 2 weeks, from the issue of March 12, 1934. Wiki link