The One Minute Geographer: Denser and Denser

Photo of Manhattan by Fabien Bazanegue on Unsplash

Another aspect US population growth between 2010 and 2020 is that the most densely populated states are getting denser — even though most of those states did not have above-average population growth rates.

The best example is New Jersey. The Garden State added almost a half-million people between 2010 and 2020. That was an increase of 5.7%, which is below the national increase of 7.4%. Yet it was New Jersey, already the nation’s most densely populated state, that added the most people per square mile: 57. That’s a lot more people driving on the Jersey Turnpike and the Garden State Parkway!

States with significant increases and decreases in population density per square mile. Data from 2020 Census; calculations by the author. (Only states with some amount of increase in population density are shown, so West Virginia, Illinois and Mississippi, ranked 48–50, are not shown on the chart.)

The One Minute Geographer did the math and there is good statistical correlation (.80) between state density in 2010 and the increase in density by 2020. You can get a quick visualization of the numbers in the chart above. I picked an increase of at least 20 people per square mile as a cutoff, and you can see that of the top six states that had the biggest increases in density, five were already among the top six most densely populated states.

At the bottom of the chart, you can see that the converse is true. Generally, the least densely populated states had the…