A Decade of Population Growth and Decline in U.S. Counties

There are a number of factors that determine how much a region’s population changes.

If an area sees a high number of migrants, along with a strong birth rate and low death rate, then its population is bound to increase over time. On the flip side, if more people are leaving the area than coming in, and the region’s birth rate is low, then its population will likely decline.

Which areas in the United States are seeing the most growth, and which places are seeing their populations dwindle?

This map, using data from the U.S. Census Bureau, shows a decade of population movement across U.S. counties, painting a detailed picture of U.S. population growth between 2010 and 2020.

Counties With The Biggest Population Growth from 2010-2020

To calculate population estimates for each county, the U.S. Census Bureau does the following calculations:

 
From 2010 to 2020, Maricopa County in Arizona saw the highest increase in its population estimate. Over a decade, the county gained 753,898 residents. Below are the counties that saw the biggest increases in population: