August Derleth (1909-1971) was an influential American writer and anthologist, best known for his significant contributions to the horror and science fiction genres. A prolific author, Derleth created the Sac Prairie Saga and is highly acclaimed for his work in expanding the Cthulhu Mythos, originally conceived by H.P. Lovecraft. As the founder of Arkham House publishing, he played a crucial role in preserving and promoting the works of Lovecraft and other major writers in speculative fiction. Derleth's passion for regional history and supernatural tales cemented his legacy as a pioneer in American literature.