Harry Warner, Jr.
Warner published his first fanzine, Spaceways, in 1938, though he had been actively sending letters to several of the professional Science Fiction magazines for several years. He was the best known LetterHack from the late 1930s through the new millennium. He wrote two full-length books about science fiction fandom and a large number of articles detailing fandom's evolution.
His series of columns entitled "All Our Yesterdays" was published by Chuck Connor in the 1980's in both print and on disc, and was one of the first electronic fanzines.
Warner was a member of the Fantasy Amateur Press Association (FAPA) for more than sixty years. It is believed that his zine Horizons was the longest continuously published fanzine in history, running from 1941 until Warner's death in 2003 after producing more than 250 quarterly issues.
The FAAn Award formerly known as Best LetterHack is now called The Harry Warner Jr. Award for Best Fan Correspondant