After each decennial Census, the US Census Bureau calculates the “center of population” for the United States, that is, if we averaged the geographic location of all US citizens, what would the average location be?

As you would expect, the average back in 1790, when the country had only 13 states along the eastern edge of North America, the population center was on the east coast. But as more states joined the country and people moved to the west and south, the population center has shifted.

Here’s a more detailed map from the Census Bureau, with some relevant population local events from US history duly noted.