a lot of it originated with the gun germs and steel book placing an overimportance on geography

I mean, there's something undeniably influential about geography on certain cultural and economic trends. It isn't a coincidence that England and Japan both became globe-spanning naval powers. And the impact of herd animals on the cultivation of disease is as undeniable today as it was a thousand years ago.

Im not saying that the south wasnt the region where slavery was the most prominent, but the south was in no way more disposed to slavery because hundreds of millions of years ago plate tectonics caused there to be a ridge formed in the south that just so happened to cause rivers to end abruptly, and people built mills there, and it’s more fertile, and oh uh a bunch of whites imported actual people as slaves because the land was just so good for slavery.

I think you're reading a bit too much into the graph headlines. The plate tectonics creating a fertile region had a political consequence because it concentrated agricultural workers in a well-defined strip of land. Those agricultural workers had a socio-economic interest that was sharply distinct from the urban shipping centers along the coast and the ranch land to the north.

This doesn't guarantee slavery. The Lakes of Minnesota and the California Valley were both fertile agricultural lands that failed to produce an active slave trade. But it does guarantee a concentration of particular industries. Not coincidentally, Minnesota and California have larger and more active labor movements concentrated in the areas where dense populations of agg workers live.

So what explains the graphic im malding about in the first place? Not geography.

Absolutely geography. That was the ahem bedrock of the split in regional concentrations of population, economic activities common to the region, and subsequent political formations within these regions.

Where the theory ultimately falls apart, though, is in assuming the political divides need to be this sharp or the populations this heterogeneous. Alabama doesn't have to be a western-oriented state scarred by settler colonialism. That strip of tectonic activity didn't summon Columbus from the ether or split the Democratic Party over desegregation. It didn't foster a slave markets in Manhattan or on the banks of the Potomic and it didn't drive the native tribes west of the Mississippi.

The shape we're seeing in the data is human history crashing like a wave on the shores of the coast and depositing individuals in the cracks left by geography. A different history would have brought different people with different socio-economic fate. But you'd still see farmers congregating along the rich soil, and those farmers would share a common interest, and that would mean something for the strip of land that wasn't as true outside it.