But I think the modern suburbs (in the USA) were more of a "white flight" phenomenon, enabled by cheaper construction methods and perhaps a confluence of a few other post-war trends/policies.

White flight swelled the population of suburbs but they were already substantial. I think it would be a misleading picture if you just choose one point in a continuous process and start from there.

We don't need to create the universe to bake an apple pie from scratch. I agree that a history of the suburbs might begin before WWII, but the general concept of needing to start at the beginning is a slippery slope. I'd say nearly all histories must pick an arbitrary start, mid-stream.

In that case I recommend the commuter train, which created inner-ring suburbs which still exist. Not exactly ancient history anyway.

Interesting, TIL. I still think modern suburbs are defined by their relationship to cars, not trains.

I think there is still, even now, a difference between these older, inner-ring suburbs with many people commuting to work by train (and generally smaller plots and the like) and newer outer-ring suburbs or exurbs (or just rings around newer cities) which are more car-focused from the start.

Technical "car" is short for "carriage" and trains have carriages.