Very interesting post from TNC on the sizable and increasing immigration of blacks back to the South and how it is and is not a mirror image of the Great Migration.
Also interesting is the response from readers to some of the places named. Apparently there was some dispute as to whether eastern Maryland counts as "the South," and Matt Yglesias questioned the southern bonafides of Miami, and the inclusion of Texas as a "historic African American population center."
Any attempt to define the boundaries of an area steeped in mythology and wrapped up in political/historical baggage is almost inevitably going to prove difficult. I remember very recently being part of a discussion of "the West" that quickly ran aground when someone asked what states qualify. Is it just the west coast and Rocky Mountain states? What about New Mexico? What about Texas, which is a "southern" state but is nevertheless wrapped up in all the mythology of the West? What about the Great Plains states west of Iowa and Missouri? Surely they aren't "Midwest," right?
Similarly goes the problem of classing states as within or outside of "the South." Is the South essentially the states that had not abolished slavery by 1860? If so, we'd have to include Delaware, and possibly Missouri. Here's one that starts a lot of arguments: is it the states of the old Confederacy? That would exclude Maryland and muddy the cases of Kentucky and Missouri, two states with conflicted populations that enjoyed representation in both the Union and Confederate Congresses.
Is it a question divorced from history, and more about current tendencies in politics, food, sports, accent, and religion? This is the basis by which people vote Florida out of the Confederacy and question the southern pedigree of places like Research Triangle, Atlanta, and Northern Virginia (and by "northern Virginia" we of course mean "most of Virginia"). But hold on: if we're talking about areas full of socially conservative evangelicals who eat a lot of BBQ, watch football, and say "y'all," not only must we include Missouri, but also Oklahoma! And probably Kansas! And New Mexico! And maybe southern Ohio and Pennsyltucky!
I also question whether a place stops being "southern" just because it undergoes cultural and demographic shifts, even significant ones. Miami may have seen a major influx of New Yorkers and Cubans and Midwestern snow bunnies, but are they not allowed to be southern? What, a group of people can move to New York and within a generation or two be "New Yorkers," but they're forever black-balled from the southern club? What about all the people in Miami who are the descendants of slaves and slaveholders? Did they stop being Southern when their Yankee neighbors moved in?
And if the majority of Chicago's south side came during the Great Migration, does that mean the south now includes that part of Chicago?