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Mean Center of Population

mean Center of Population

The mean center of population keeps moving west

The center of population has moved nearly 900 miles from its original location in Kent County, Maryland. In those 230 years, the nation has grown and expanded, and the center of the U.S. population has marched steadily westward — through Ohio, Kentucky, Indiana, and then Illinois. In recent decades, it has tilted towards the Southwest as people moved to the Sun Belt and immigrated from the southern border. Since 1980, that center has been in various locations in Missouri. In 2020, the center was near Hartville, a small city about 45 miles east of Springfield.

A Population on the Move

One of the most fascinating implications of knowing the location of the center of population is that it helps us track our country’s growth and population movement decade by decade. Americans have been inspired to move for a variety of reasons from economic opportunity to transportation and technological advancements that made internal migration easier. The graphic below visualizes the direction and distance of change of the mean center of population from decade to decade.

Territorial expansion played a major role in the early westward and southern movements of the center of population. The map below shows the territorial expansion of the United States overlaid with the movement of the mean center of population for each decade from 1790 to 2020.