Robert Sobel was an American professor of history at Hofstra University, and a well-known and prolific writer of business histories. He was also a chess Master, who represented the United States at the 1957 and 1958 Student chess Olympiads; he defeated thirteen-year-old future World Champion Bobby Fischer at Montreal 1956.
Despite his prolific writings in business history, he is most famous for his single novel, For Want of a Nail, an alternate history of the United States.