America's Diverging Migration Patterns

In general, America’s population “center” has been moving south and west over the past century or so. The map below, from the U.S. Census, shows the steady march of what’s more technically referred to as the nation’s center of population—which identifies the single geographic point that divides the nation’s total population from north to south and east to west—since the late 18th century. Understanding where the nation’s population center is and where it is heading helps us understand the big demographic shifts that are shaping our nation and its cities.

But there is not just one population center. According to a new study published in the Annals of the Association of American Geographers, this point actually varies pretty widely depending on what group or demographic phenomenon you’re looking at. The study, by David A. Plane from the University of Arizona and Peter A. Rogerson from SUNY, mapped the population centers for key demographic groups—gender, race, and age—and also for the key components of demographic changes like births vs. deaths and domestic vs. international migration.