Yeah basically the country was blowing up in birth rates and suburban expansion post WW2 at the same time the car was becoming a big thing and people were able to afford them. So auto companies lobbied and campaigned heavily to make everything very car-centric in the US and now this is the result. It really fucking sucks.
Also doesn't help that the country is so damn big, but that's a poor excuse for the lack of proper transit at the metro area level.