Here's the same background on these I gave yesterday. I stopped counting at the 2010 season because the thing for which I'm creating these relates to the recent round of realignment that's been going on. The data I got comes from James Howell's database, as queried by Chris Stassen's site. The thickness of the lines corresponds to how many games have happened during the series. A thicker line means more games.
Georgia and Auburn are not only Florida's two oldest rivals, but from 1956 to 2002 (except 1992), they were always back-to-back on the Gators' schedule. Many Gator fans, my father included, refer to that pair of games as the Amen Corner of the slate. From 1956-89, the Gators beat both of them in the same season only five times: once per decade plus an extra time in the '80s. Steve Spurrier changed everything about Gator football in 1990, this trend being no exception, and he swept them in eight of his 12 years in Gainesville. Also, Florida is the sole remaining original SEC school to have two historical series with teams that have never been SEC members themselves. Well, that stat goes for the time being anyway. If Florida and Miami don't schedule any more games beyond this fall's matchup, and it doesn't sound like too many are coming soon, UM will disappear from the map in 2022.
Georgia is one of the pair of SEC East schools that had built up 100 years of history with two schools by 2010, as its Auburn and Georgia Tech series had hit the century mark by then. It also seems to be pretty handy with naming its rivalries. The three lines coming out of the bottom of the G there are the school's oldest three series, and they go by the Deep South's Oldest Rivalry, Clean Old Fashioned Hate, and the World's Largest Outdoor Cocktail Party. Nicknames that good are better than the tacky rivalry trophies of the Big Ten if you ask me.
Most of the historical series within the league are pretty tightly distributed in terms of geography. Some of UK's series certainly qualify, but I don't have a good answer as to why the SEC's northernmost school has a long history with the SEC's two southernmost schools. Kentucky also is unique in the league as it has a long, if relatively infrequent, series with a Big Ten team: Indiana. The two of them have played 36 games dating back to the 1890s.
If you thought the maps for Arkansas and Texas A&M looked a bit different thanks to their SWC roots, then this must look like a foreign land. This is not Big 12 territory; this is Big Eight territory. This is the only one of the 14 maps that doesn't have even a slice of the Gulf of Mexico, and it's one of two (along with Texas A&M's) without a school in a state east of the Mississippi. You might also notice that these lines are pretty thick; five of the six represent at least 95 total games played. If there's one thing that has suffered the most since the 2010 realignment episodes began, it's the heritage of the Big Eight. Former members now are in four different leagues thanks to moves in only the past three years.
From Big Eight country, we go to ACC country here. South Carolina is not TCU, by any stretch, but it has moved around leagues a bit. It was an old Southern Conference member since the days before the SEC split off of it, but it stayed in until becoming a charter ACC member in 1953. It went independent in 1971 due to disputes with the league, and then everything but football went into the Metro Conference in 1983. Finally, it became the SEC's 12th member in 1991 after FSU rebuffed the conference's advances. It has most of its historical series with its old SoCon and ACC foes, though UGA provides one old connection within the league. Only Clemson is a truly strong rival, with the Gamecocks having over 100 games against the Tigers under its belt but fewer than 60 with the others (as a major school, per James Howell's database) as of 2010.
Tennessee is the introvert of the conference. It has only four historical series by my rubric, but they're all really strong ties. Well, three of the four are, anyway, as UT has over 90 games with Alabama and more than 100 each with UK and Vandy. The reason for this situation is that, in general, UT historically had a lot more games with teams that ended up in the West than the ones in the East. To this day, the Vols still have more games played with Auburn and Mississippi State, respectively, than either of Florida or Georgia despite two decades of divisional play. It also played Georgia Tech quite consistently from just after WWII to the late 80s, but it didn't play the Jackets much before and haven't played them since. If divisional play continues as we know it, there won't be a new team on this map until Florida joins it in 2036.
Vanderbilt's historical series basically match Tennessee's, except it has Georgia on here as well. The difference is that instead of playing Georgia Tech to get into the Peach State, Vandy went with the Bulldogs instead. As mentioned yesterday, Vandy is the only school with a decent-sized history with Sewanee (officially the grandiosely monikered University of the South), but that charter member left the SEC too long ago to make an appearance on any of these maps.