From the map it seems like all the cases are in the Southeast. Is the Southeastern United States sort or a 3rd Word Country within the U.S. ? It seems like every time I see something like this it is in the Southeast. It seems to me like the rift from the Civil War has never completely been resolved. Just an observation, does anyone else feel the same way?
I'm from France; when I lived there, I used a network of cheap state-subsidized subway and trains to get around the country and see friends and family; I attended a good university for a mere few hundred euros a year; I would buy fresh food at the local market every week; my friends from poorer families got free meals at the university, housing stipends, and so on; my healthcare was covered; and many other things that escape me right now.
I also lived in Louisiana; besides New Orleans, what I've seen are old decrepit roads that haven't been restored in decades, public transportation only used by the very poor and mentally ill (very often correlated), neighborhoods next to the university campus that I've been told to never cross for risk of getting shot, almost half of the people being dramatically ill (overweight), lifeless minuscule downtowns. And heck, even New Orleans is still a shitshow.
Present all the economic arguments that you want, as someone who has lived in both places, a lot of the south of the US feels like a terribly dreary place to me. And I've lived in plenty of places, and have found things to like in all of them- this is not just me being close minded, I just found the south of the US to be in a terrible state for being a part of the world's leading superpower.
I've been living in California for many years now, which is orders of magnitude more pleasant and which I love in many ways (although rife with flaws as well; notably the shameful income gap in Silicon Valley).
You want per capita, otherwise you'd think China is wealthier than Switzerland. And you want PPP (though it doesn't make that much difference) since that reflects what people can actually afford. If you made $1M a month but the prices in your country were such that it would only buy dry bread and water, you'd still be poor.
It depends on where you are. Certainly on average there are more poorer areas, but there are plenty of nice areas as well. Atlanta, Nashville and a few other places are really nice.
Edit: Also 3rd world is a bit hyperbolic. Even the bad areas of the southeast aren't comparable to most of Africa and the real 3rd world.
Look at a map of "percentage Black". The number of issues associate with race, will be correlated both with how Black people are treated, but also the number of Black people.