[dragonwriter]

> It may not seem obvious now, but prior to the suburbs, a lot of people lived in ragged tenement buildings that were in bad shape.

A lot of people still do. The people that could afford to move to the suburbs were also people that could afford to move out of tenements in the city, too, generally.

OTOH, it allowed them to be farther from (and outside shared facilities like schools, etc., with) the tenements and the people stuck living in them. (Which, due to economics and outright, overt discrimination in both lending and things like restrictive real estate covenant, especially meant non-Whites.)