Hughes Loses, William Gaines: The Horror Titles
The EC titles were the first really successful horror comics, and as such it was they who spawned imitators, not Adventures Into The Unknown.
"Readers Guide to Pre-Code Horror" #7, Lawrence Watt-Evans / Comics Buyers Guide
Since the appearance of "AITU" several years ago, we have published more than 30 million copies! [Author's note: over 638,000 copies an issue!]. Rather impressive, wouldn't you say?"
Adventures Into The Unknown # 49 ( November 1953) letters page
Despite the commonly held misconception that EC Comics publisher William Gaines created horror comics with the release of The Vault Of Horror ( April-May 1950), Tales From The Crypt ( October- November 1950) and The Haunt Of Fear ( May-June 1950), it was actually Richard Hughes, through the American Comics Group, who did so, beating Gaines to the punch by over a year. The first issue of ACG's Adventures Into The Unknown appeared in the fall of 1948. This introduction of the horror genre into the art form is arguably the most important contribution that Hughes and ACG made to the history of comic books.