Do have a citation for the definition of suburbs that that figure is based on?

In many East Coast cities, and at least some Midwestern cities, there were these things known as “streetcar suburbs”. As the name implied, they were suburbs connected to the main city through a network of public transit. In some places, these areas would be absorbed by the growing metropolis but in others they remained independent cities. Now they are sometimes called “inner-ring” suburbs.

In the Boston area, for instance, Brookline, Cambridge, Somerville, Newton, Roxbury, Dorchester, Roslindale, Brighton, and others were all at one point street car suburbs. The last four were annexed by the city of Boston in 1868, 1870, 1873, and 1874, respectively, while the first four remain independent to this day. Annexation is the fate of a lot of street car suburbs across the country, as they often wanted municipal services (in many places, fire departments, water, and sewage were particularly attractive) that the larger city was better equipped to provide.

The proto-street car suburbs could Brooklyn and Queens where people commutes even before they development of streetcars—they used ferries, and until 1898 were formally suburbs. I have a longer post about the development of New York here.

Which is one of the reason I’m curious about the exact definition used—would places like Brooklyn and Brighton have still counted in that statistic? Is it based on municipal boundaries or something like density?

Many of these suburbs were founded for the bourgeoise or elite who wanted clean air and more space. While exactly who lived where depended on the make up of the city, in general the suburbs were well to do. In the 1920’s, University of Chicago sociology professor Ernest Burgess proposed that the city was made up of concentric circles radiating out.

At its center lies a Central Business District. The next circle out Burgess called the Zone of Transitions, which includes factories and cafes and old tenements. Beyond that is the Zone of Workingmen’s Homes, where factory workers, recent immigrants, and low-skilled workers would live. Beyond that the more respectable Residential Zone, generally made of detached single family homes. And beyond that still we have our fifth zone, the Commuter Zone, where people obviously had to have the money to commute in every day, often typified by large homes and gardens... but at times giving way to farmland quickly. Depending on the municipal lay out, either of those last two could technical be suburbs, if our definition is based on municipal boundaries as I believe it frequently was at the time. They’d generally house white collar workers during this period, from clerks all the way up to the owners of major enterprises. You can see good maps here, including maps actually applying the model to a real city (Chicago), and more about the different zones here.

The thing is, while everything is neat in that model, in reality it’s more complicated and there’s a tremendous mix of who lives in these suburbs. Burgess himself recognized that natural and social features “distorted” this abstract model (in Chicago, you have the River and the Lakeshore on one hand and the railway lines and the Black Belt on the other hand). And, beyond that, as later sociologists recognized, there were also smaller centers which had their own gravitational pull—often at one point these were downtowns of once independent cities. If we stick with Chicago, perhaps the most famous is Pullman, which functioned as essentially a mill-town (making the then world-famous Pullman rail cars) that was absorbed by the city.

And, to make matters more complicated, the concentric circles didn’t need to respect the existing municipal bounciest. So in the immediate pre-War era, we have areas like the Hamptons just outside of New York, which held wealthy people who commuted to the city from mansions, as described in the Great Gatsby, and then you also have areas like East Cambridge, Massachusetts, which was largely working-class first and second generations Italians, as a second Italian neighborhood in the Boston area, after the famous North End. Socially and economically, it wasn’t significantly different from other ethnic enclaves in industrial cities; it just happened to say “Cambridge” instead of “Boston” on the mail. I did some research on the area for my brother-in-law’s family and it seemed like many in East Cambridge (just like people in Brooklyn of the same era) worked in factories and other operations in Cambridge itself, rather than crossing the river into Boston. During this period, East Cambridge had significant populations of Italians and Portuguese, settling next and ultimately replacing many of Irish who dominated the area from the mid-19th century (this pattern of co-religionists, not just co-ethnics, settling together is a common one). My brother-in-law’s great uncle ended up growing up to be a major national figure in the union movement—I believe his family had people who worked in both a chicken slaughterhouse and a plastics factory, to give you a sense of East Cambridge at the time.

And slightly further afield in the Boston area you have mill-towns, too distant for most commuters but still in the same metro area, like Lawrence, Lowell, and Waltham (Lawrence and Lowell produced textiles, Waltham was famous for its watches and is still officially nicknamed “watch city”). These are urban areas of their own, with their own concentric circles in the Burgess model, but I wonder if they’d be captured in definitions of suburbs.

And then you have by the same token primarily working class farming communities (as most of, for example, Boston’s Metrowest area was—towns like Concord and Lexington) where some of the rich “gentleman farmers” had large estates and where the men of the family might travel to the city daily to deal with their firm. By the early 1930s, this sort of gentleman farmer was rarely actually a gentleman farmer (in that, he just had a large estate rather than working it as a productive farm) but many of these families still held these large rural estates and commuted to the city as necessary, first by train and then later by automobile. Here’s an example of one in my hometown owned by a family of what today we’d call real estate developers. The Boston neighborhood of Codman Square, for example, is named for them. This is one of a handful of such former gentleman farmer houses in the area, generally the very rich who had business in Boston. I checked the website of another, which is owned by the town and commonly rented out for weddings and similar events and it just says, “The Pierce House was built in 1900 by John H. Pierce, a gentleman farmer and businessman about whose affairs we know very little,” but another, now a well-know art museum and sculpture park, was build by a business man who dealt in various imports and owned a large glass factory. However, despite these handful of large estates, most people in town were just farmers, I believe in the pre-War period especially dairy farmers. It was a rural area that still had a few people who commuted to import business in the city.

So, in short, depending on exactly what suburbs and what counted as a suburb in this definition, we can be talking about everything from middle class clerks to millionaires to farmers to factory workers. The suburb-qua-suburb really didn’t coalesced until the widespread availability of cars, the construction of highways, and planned communities based on pre-fab houses sharing the same floor plans. Levittown, widely recognized as the first modern suburb, only popped up in 1947.