L. Sprague de Camp
Lyon Sprague de Camp known as L. Sprague de Camp was an American writer of science fiction, fantasy, nonfiction and biography. In a career spanning 60 years, he wrote over 100 books, including novels and works of nonfiction, including biographies of other fantasy authors. He was a major figure in science fiction during the genres heyday in the 1930s and 1940s.
De Camp was born in New York City, one of three sons of Lyon de Camp, a businessman in real estate and lumber, and Emma Beatrice Sprague. His maternal grandfather was the accountant, banker, pioneering Volapkist and Civil War veteran Charles Ezra Sprague. De Camp once noted that he rarely used pennames, partly because my own true name sounds more like a pseudonym than most pseudonyms do.
Source: Wikipedia