Donald A. Wollheim

Donald Allen Wollheim was an American science fiction editor, publisher, writer, and fan. As an author, he published under his own name as well as under pseudonyms, including David Grinnell, Martin Pearson, and Darrell G. Raynor. A founding member of the Futurians, he was a leading influence on science fiction development and fandom in the 20th-century United States. Ursula K. Le Guin called Wollheim "the tough, reliable editor of Ace Books, in the Late Pulpalignean Era, 1966 and '67", which is when he published her first two novels in Ace Double editions.

Source: Wikipedia (CC BY-SA 4.0), https://en.wikipedia.org/wiki/Donald_A._Wollheim