Have you ever wondered where the middle of Minnesota is located? Or where to find the center of South Carolina? Every state has a middle. And there’s more than one way to measure that.
There are at least two ways we can think of the middle of geographic areas. Beyond their shapes, geographic areas have other attributes—like populations. It is possible to calculate the middle of either one, arriving at the center of geography or the center of the population.
Geographic centers are complicated by the fact that geographies are often nested. States are part of countries, and countries may be grouped by other areas, like continents, hemispheres, or a political or economic body. The US is also commonly referred to in three distinct ways: as simply the United States the continental United States, which excludes Hawaii; and the contiguous (or conterminous) United States, which excludes both Alaska and Hawaii. The latter is frequently referred to as the “lower 48,” and all of these include the District of Columbia. By virtue of these classifications, the US could potentially have multiple geographic centers.
Using data from the US Census Bureau, we mapped the geographic center of every state and the territory of Puerto Rico. We also did the same for each state’s population center, which is the average location of all the people within that state. Each city’s location tugs on this average, with more populated cities having the strongest pull. The map shows the distance between each state’s population center and its geographic center. Our map also shows the geographic centers of all 50 US states, as well as those of just the lower 48.
It is generally intuitive that smaller states typically have smaller distances between the centers of their geography and the centers of their population. Larger states have more available space, after all. But people do not evenly distribute themselves across a state, and cities are settled in various locations due to a number of factors. People also move, so—unlike their geographic counterparts—population centers are more dynamic. The population center of the US has shifted considerably, moving from the East Coast in 1790 to southern Missouri by 2020.
Change is the only constant. And this map demonstrates how that concept takes center stage in geography. Whether by the inescapable march of time or the numerous ways we conceptualize and categorize the world around us, there’s always more than one way to measure—and map it.
