An interactive picture of Americans perpetually on the move.

You can tell a lot about a place by who doesn't want to be there any more. Or, conversely, by who wants to move in. 

A city that seeps population over time invariably has deeper problems driving its demographic change, like poor school districts that can't keep young families, or weak job prospects for its college grads. A county that attracts new residents, on the other hand -- maybe young people in particular, or retirees -- likely has the right amenities to lure them. Maybe a certain job sector. Or golf course communities.

In this way, we can divine some of the fortunes of different corners of the country simply by watching how Americans move around over the years. Each year, about 10 million Americans relocate to a new county. Map all those moves from one Census to another, across decades, and by race and age demographics, and you can see the Great Migration of blacks from the South, white flight to northern suburbs, the hollowing out of Rust Belt cities and the rise of the Sun Belt.

Researchers at the University of Wisconsin, Michigan Technological University and the University of New Hampshire have built just such a database dating back to the 1950s. Their tool tracks net changes in population by county, all across the country, for each decade since the 50s (taking into account estimated deaths and births in between each decennial Census). The results tell hundreds of stories, but we've pulled out a few of them.

Here is a map of total net migration across the 2000s in the U.S., with orange counties losing the most people and purple counties gaining the most. The legend is shown at right.

Net migration in total population by county during the 2000s.

At that largest scale, broad patterns emerge as the two coasts and much of Texas gain population at the expense of the Great Plains during the 2000s. Here is a different picture, over the same period, looking only at net migration by 15-29 year-olds (based on their age at the end of each decade):

Net migration of 15-29-year-olds during the 2000s.

Zoom in -- you can do this on the full interactive map here -- and it's clear that Rust Belt counties around Detroit, Cleveland and St. Louis have lost many young people, who have relocated, on balance, to places like San Diego, Austin, and Atlanta. The mapping tool also illustrates these population changes in chart form. Here, those six counties are contrasted with their migration trends by age:

The tool also illustrates some familiar historical patterns by race. In this map, from the 1970s, white populations have clearly left major Midwestern cities like Chicago, Detroit and Cleveland, with increased in-migration into surrounding counties:

Net white migration during the 1970s.

Wayne County (Detroit) lost 26.6 percent of its white population in the 1970s. Cook County (Chicago) lost 15.5 percent, and Cuyahoga County (Cleveland) 20.1 percent.

A generation earlier, in the 1950s and 1960s, we can see a related chapter in history, in the broad migration of non-whites (as the Census collectively classified minorities then) out of the South and into much of the rest of the country:

1950s


Nonwhite net migration in the 1950s.

1960s

Non-white net migration in the 1960s.

You can zoom in here for a closer take on individual communities. Each map shows a relatively simple calculation (the total population in each county at the end of a decade, relative to what it was projected to be at the beginning). But that one number, particularly when compared to other counties nearby or across the country, reflects much about what may have happened in the interim years.

All images courtesy of the net migration mapping tool created by the Applied Population Laboratory at the University of Wisconsin.

About the Author

Most Popular

  1. Transportation

    With Trains Like Schwebebahn, No Wonder Germans Love Public Transit

    Infrastructure like this makes it clear why Germany continues to produce enthusiasm for public transit, generation after generation.

  2. Transportation

    You Can’t Design Bike-Friendly Cities Without Considering Race and Class

    Bike equity is a powerful tool for reducing inequality. Too often, cycling infrastructure is tailored only to wealthy white cyclists.

  3. Equity

    Capturing Black Bottom, a Detroit Neighborhood Lost to Urban Renewal

    “Black Bottom Street View,” now exhibiting at the Detroit Public Library, thoughtfully displays old images of the historic African American neighborhood in its final days.

  4. Amazon HQ2

    New York’s Ejection of Amazon Is the Start of a Movement

    NYC lawmakers who led a resistance campaign against HQ2 are declaring victory. And already, they have plans to escalate their opposition to tax incentives.

  5. Amazon HQ2

    Without Amazon HQ2, What Happens to Housing in Queens?

    The arrival of the tech company’s new headquarters was set to shake up the borough’s real estate market, driving up rents and spurring displacement. Now what?