FAYETTEVILLE, Ark. (KNWA/KFTA) — On November 16, the U.S. Census Bureau will announce where the U.S. center of population was in 2020, a way to summarize population shifts every decade.

The center of population is the place where an imaginary, flat, weightless and rigid map of the United States would balance perfectly if everyone weighed the same.

According to a release from the census bureau, the colonial town of Chestertown, Maryland, near the Chesapeake Bay, was once a major port for the trade of tobacco and enslaved people and was the center of population in the new United States in 1790 when the first census was taken.

Since then, the geographic center of the U.S. population has progressed steadily westward, through Ohio, Indiana and then Illinois.

In recent decades, it has tilted to the Southwest as people moved to the Sun Belt and immigrated from the southern border.

“It’s amazing how the population just took huge leaps, starting off with about 3 million people and then, all of a sudden, tens of millions of people,” said Sharon Tosi Lacey, the Census Bureau’s chief historian. “Immigration has played a huge part in that.”

Since 1980, that center has been in various locations in Missouri. In 2010, the center was near Plato, a small town about 75 miles northeast of Springfield.

The point is officially marked with a survey monument by the National Oceanic and Atmospheric Administration’s (NOAA) National Geodetic Survey (NGS), the U.S. government authoritative source for precise latitude, longitude and elevation measurements.

Since 1990, the Census Bureau and NGS have placed the center of population monument in a publicly accessible location near the actual center of population.

According to the Census Bureau, knowing the center of population helps geographers, demographers and others quantify how fast and in what direction Americans are moving.