At the beginning of Volume 1 - Men and Magic of the Original 1974 Dungeons & Dragons it says (with emphasis added):
Yes, his influence is throughout the original game.Dedicated to all the fantasy wargamers who have enthusiastically played and expanded upon the CHAINMAIL Fantasy Rules, with thanks and gratitude. Here is something better! Special thanks to the Midwest Military Simulation Association, the Lake Geneva Tactical Studies Association, Rob Kuntz and Tom Keogh (in memorium).
Best of all, he is my friend. Join me in celebrating his birthday today!!