Note: I have not delineated between "full" and "basketball only" members in the graphics, mostly because that would turn them from "visually interesting" to "Oh my God! MY EYES!!!"
The Sun Belt is, by a pretty wide margin, the oldest of the conferences that we will be covering here at Underdog. The conference started way back in 1976 as a basketball-only conference that featured South Alabama, Georgia State, Jacksonville, UNC-Charlotte, South Florida, and New Orleans.
After a few years, things shifted a bit. In 1979, Alabama Birmingham and Virginia Commonwealth joined. In 1980, the conference decided that New Orleans' gym was too small to participate in the conference (among other problems), and kicked them out. A year later Georgia State left and a year after that Old Dominion and Western Kentucky joined.
Things were quiet for a while, but then in 1991 everyone departed the conference save for Jacksonville, South Alabama and Western Kentucky, which led to a life-saving merger with the four-year-old American South Conference. This brought New Orleans back, and it also added Central Florida, Lamar, Texas-Pan American, Louisiana Tech, Arkansas-Little Rock, Arkansas State, and Louisiana Lafayette. Central Florida then changed their minds and left the next year.
At now 15 years of existence, the Sun Belt was still a basketball-only conference, but things would begin to change again before the 90's were over. Jacksonville, Lamar and Texas Pan-American would leave and Florida International would join in 1998, and the following year the University of Denver would join. Two more years would finally bring football to the list of sports sponsored by the SBC. It would also bring New Mexico State, North Texas and Middle Tennessee State, as well as Idaho and Louisiana-Monroe for football only, whose additions would offset the departure of Louisiana Tech.
All of a sudden the Sun Belt had seven football teams, and there was relative quiet over the next decade or so. Utah State joined for only football in 2003, Troy did the same in 2004, and then Utah State abruptly left for the WAC along with New Mexico State and Idaho in 2005, to be replaced by Florida Atlantic. At this point the Sun Belt had eight football teams, 12 basketball teams, and all was reasonably status quo.
In 2009, Western Kentucky finally got a football team, and a year later New Orleans left again. In 2012 Denver departed for a more geographically logical conference, and South Alabama became the next-to-last historical straggler to add on a football program (Arkansas-Little Rock still does not). Then as you all recall, last year things got a little hectic.
Florida International, North Texas, Middle Tennessee State, and Florida Atlantic all left for Conference USA, while Georgia State returned to its roots as a full member. The conference also added Texas State as a full member and Texas-Arlington as a basketball member, moves that in part led to the demise of Western Athletic Conference football. This meant that when Western Kentucky left this past offseason to (surprise!) join Conference USA, New Mexico State and Idaho returned as football-only members, and both Appalachian State and Georgia Southern jumped up from FCS this season as full members to keep the conference at 11 football teams.
So there you have it. A visual and verbal run down, and now you are up to speed with all the Sun Belt's comings and goings in its history. Also, feel free to debate my incredible graphic skills.