Metropolitan America


The rural to urban exodus is well known. It has driven the growth of the largest urban areas from one million residents as late as 1800 to nearly 40 million today. The United States has risen from less than 40 percent urban in 1900 to more than 80 percent today. Other, more affluent nations have experienced similar trends. Even more quickly, China has risen from 19 percent urban in 1980 to 56 percent in 2015 today, according to the United Nations. Even the least affluent nations are urbanizing rapidly.

The Defining Trend: Metropolitanization, not the Rural to Urban

But the trend reflective of urbanization is the movement of people into metropolitan areas, which include traditional (core) city, suburban and even rural areas. This might best be called “metropolitanization.”

According to the US Office of Management and Budget, a metropolitan area is “a geographic entity associated with at least one core … plus adjacent territory that has a high degree of social and economic integration with the core as measured by commuting ties" (Note 1). The core is the largest urban area in the metropolitan area. The peripheries of metropolitan areas, outside the largest urban areas, are largely rural by the Census Bureau definition. In 2010, the majority of the nation’s rural population lived in metropolitan areas, while 90 percent of metropolitan land area was rural. Despite living areas formally designated as rural, residents in the metropolitan periphery more often live an urban, rather than rural lifestyle.

Cities, in the economic sense, are metropolitan areas, which can also called "functional cities" or "economic cities." By this is not meant any jurisdictional definition, such as the city of New York or the ville de Paris, but rather the entire area of economic integration generally defined by work trip commuting. Former principal planner of the World Bank Alain Bertaud has shown that in this sense, cities are labor markets.

There is considerable confusion, however, about the commuting that defines a metropolitan area. Many people think of the city as monocentric, with most of the employees working in a central business district (downtown). Yet all of the major US metropolitan areas are more decentralized than monocentric or even polycentric (this includes New York, with the world’s second largest central business district).

Metropolitan areas are defined by commuting to or from central counties, which encompass most, if not all of the largest urban area. Thus, the New York metropolitan area is not determined by commuting to Manhattan or even commuting to the city of New York. The New York urban area is so extensive that, for example, Ocean and Mercer counties in New Jersey as well as Westchester, Nassau and Ulster counties in New York are central counties. Commuting to any of these (and many other) counties counts toward their inclusion in the metropolitan area.

Over the past century or more, the United States has transitioned from a non-metropolitan to a metropolitan country.

1900: Non-Metropolitan America

Until the late 19th century, there was only limited commuting from beyond the urban periphery to cities. By 1900, not only had improved mass transit spurred development outside the city limits, but the automobile was about to make longer commutes possible, saving time in the process, and making access to more of the metropolitan district possible. For practical purposes, the 1900 census was the last of the pre-automobile era, with only 8,000 cars registered across the nation. By 1910, the number had increased to 450,000, and more than 8,000,000 by 1920. According to economist Robert Gordon, 90 percent of the world's registered motor vehicles were in the United States by 1930 (Note 2).

In response to these trends, the US Census Bureau began designating “metropolitan districts” in the 1910 census. These metropolitan areas had urban core municipalities of at least 50,000 residents.

A 1948 Census Bureau publication (The Growth of Metropolitan Districts in the United States: 1900-1940) produced retrospective estimates of population for the 39 metropolitan districts with more than 100,000 population in 1900. These metropolitan districts had a population of 19 million. There were 59 million US residents outside the metropolitan districts.

Early metropolitan America was much different than today (Table).

New York was the largest metropolitan district in the nation, with 4.7 million residents, 3.4 million of whom lived in the city of New York. At that time, there was plenty of greenfield space in the outer boroughs to accommodate the more than 150 percent increase that occurred in the ensuing decades (see 1908 bird's eye view from the David Rumsey Map Collection).

Chicago was the second largest, with 1.8 million residents, more than 90 percent of whom lived in the city of Chicago. Philadelphia had 1.6 million residents, with 80 percent in the core city. Boston had 1.2 million residents, but suburbanization was well on its way, with only 44 percent of the population in the core city.

Los Angeles, which has been the nation's second largest metropolitan area since 1960, had 123,000 residents in 1900, 35th largest of the 39. Dallas-Fort Worth and Houston, now ranked 4th and 5th largest, did not achieve metropolitan status until 1920. Now seventh ranked Miami had to wait until 1930 for metropolitan status.

Two 1900 vintage metropolitan districts have become part of larger metropolitan areas. Lowell, Massachusetts was combined into Boston, while Fall River, Massachusetts became a part of the Providence metropolitan area.

Scranton--Wilkes-Barre, Pennsylvania has grown particularly slowly and has fallen from 13th largest in 1900 to 100th largest in 2018.

2010: Metropolitan America

Between 1900 and 2010, the number of metropolitan areas increased to nearly 10 fold (383). Their population had risen by 263 million, more than 13 times their 1900 population. Meanwhile, the number of residents living outside the metropolitan areas dropped 13 million to 46 million (Figure 1). In 2010, 85 percent of the nation's population was in metropolitan areas, up from 25 percent in 1900. If the metropolitan areas with smaller urban cores are counted, only six percent of the nation (or 18 million people) is non-metropolitan.

Metropolitanization has also meant growing suburbs and exurbs. By 2010, metropolitan areas with more than 1,000,000 population had only 26 percent of their population in the historical core municipalities. By contrast, among the 32 metropolitan districts corresponding to today's metropolitan areas with more than 1,000,000 residents, the historical core municipalities had 80 percent of the population in 1900.

Metropolitanization is continuing. Between 2010 and 2018, 99.5 percent of US growth has been in metropolitan areas. This should not be surprising, because so much of America’s economy is in this all-encompassing sector of the nation, with 85 percent of the GDP produced in the hundreds of metropolitan areas ranging from the largest, to those with only 150,000 residents.

Metropolitan Districts (1900) & Metropolitan Areas (2010)
1900 Rank Metropolitan District/Area 1900 2010 Notes
1 New York       4,607     19,567
2 Chicago       1,838       9,462
3 Philaelphia       1,623       5,966
4 Boston       1,250       4,553
5 Pittsburgh          792       2,356
6 St. Louis          650       2,788
7 Baltimore          578       2,711
8 Cincinnati          496       2,115
9 San Francisco          478       4,336
10 Cleveland          420       2,077
11 Buffalo          394       1,136
12 Minneapolis-St. Paul          373       3,349
13 Scranton--Wilkes-Barre          371          564
14 Milwaukee          325       1,556
15 Detroit          319       4,296
16 Providence          306       1,601
17 Washington          306       5,636
18 New Orleans          295       1,190
19 Albany          283          871
20 Louisville          260       1,236
21 Lowell          257 Merged into Boston
22 Kansas City          223       2,009
23 Worcester          202          917
24 New Haven          196          862
25 Fall River-New Bedford          188 Merged into Providence
26 Rochester          185       1,080
27 Indianapolis          174       1,888
28 Omaha          162          865
29 Denver          147       2,544
30 Columbia          143       1,902
31 Toledo          140          610
32 Memphis          130       1,325
33 Richmond          130       1,208
34 Syracuse          127          663
35 Los Angeles          123     12,829
36 Atlanta          121       5,287
37 Birmingham          115       1,128
38 Dayton          112          799
39 Nashville          111       1,671
Population in 000's
From Census Bureau


Note 1: This includes smaller metropolitan areas, which are called “micropolitan areas” by the US Census Bureau. A micropolitan area has a core urban area of from 10,000 to under 50,000 residents, while the term “metropolitan” applies to areas with 50,000 or more residents.

Note 2: See Robert J. Gordon, The Rise and Fall of American Growth: The U.S. Standard of Living Since the Civil War, page 374, reviewed at


Photograph: Ed Koch Queensbury Bridge (1908), New York (creative commons)