An acknowledgment in the front matter of the original Dungeons & Dragons game made the name of the Midwest Military Simulation Association (MMSA) immortal. At the time that Dungeons & Dragons came out, the MMSA was a sizable gaming club in the Twin Cities, which, as this summer 1974 flier shows, played a number of different types of games, not just fantasy. The name "MMSA," however, was of relatively recent origin.
Back in 1965, Dave Arneson and several other local gamers who would be associated with Blackmoor (including Dave Wesely, Pete Gaylord, Dan Nicholson and Greg Scott) were members of the Twin Cities Military Miniatures Club. As the same suggests, this club was not primarily focused on gaming: many of its members were miniature collectors rather than wargamers. The younger members, including Arneson, had been introduced to gaming through Avalon Hill, and learned miniature wargaming in the company of these collectors.
In April of 1969, while a student at the University of Minnesota, Arneson began discussions with several professors about forming a wargaming group within the school (no, Professor Barker was not among them). The result was the formation of the University of Minnesota Military History Club, which subsumed the prior Twin Cities club, but required that two-thirds of its officers be U of M students. The primary impetus behind this restructuring was to gain access to university space for gaming; Arneson especially coveted the space for his Fletcher Pratt naval wargames. We see that issues of Corner of the Table from this era state this affiliation quite boldly.
However, this status quo could not be maintained forever, as eventually many key members of the group would graduate. On November 19, 1971, Arneson announced in Corner of the Table that he would be forming a "companion group made up of non-students." The first Corner of the Table of 1972 names this outside group the MMSA. The U of M MHC retained its own authority but affiliated with the MMSA, as did several other clubs, including the Military History Club of the College of St. Thomas. By the fall of 1972, activities related to Blackmoor were conducted "almost exclusivey" at St. Thomas, though still under the broad auspice of the MMSA. A year later, a contemporary account asserts that the MMSA had "about 35 members of which 20 are 'full time' active members." It was this body that playtested the drafts of Dungeons & Dragons and earned the nod at the front of the rules.