[Earw0rm]

This is a recent phenomenon.

The original reason for low population density was agricultural work, which - even in the early days of mechanisation - was plenty physical.

Living in exurbia to work and consume like a city dweller is a new kind of stupid.

[Schiendelman]

Yep, and we caused it, through the massive subsidy to cars that was the federal highway program. Many tranches of spending, from ~1937 forward, caused this.