Or Panama City, did not reach 1 mil until the 90s
And "designed with cars in mind" is part of the problem, is it not? Using that as a filter is like saying "there are no parking garages with good canoeing routes"
Those other cities have a population that is adjusted to the heat - they grew up with it, their ancestors grew up with it, they're genetically and culturally adjusted to the climate. By contrast, the U.S. South includes a large number of immigrants who are only there because air conditioning exists. It's a mystery why anyone would want to walk around in 100 degree heat with 90% humidity, because they certainly wouldn't.