The map below was one of the more interesting maps produced after the census in 2010. It shows how the United States’ demographic center of gravity has shifted westward each census since the first in 1790. The center of population is essentially the point on which a flat, firm map of the United States would be perfectly balanced — somewhat like a seesaw — if all its residents had the same weight.

What is this map good for?
There are a myriad of ways to map a population, but as useful as maps can be they typically contain a large number of data points which can make interpreting them difficult. The main strength of a center of population map is its simplicity, just the location of America’s center of population can reveal a good deal about the country. With some historical knowledge a map of the country’s previous centers of population can reveal a number of macro trends in U.S history. For example, in 1890 the Census Bureau announced that the western frontier had finally been settled, as the map above shows, the U.S center of population would move west much more slowly afterwards.

After looking at the United States map, I created the interactive map below of each state’s center of population over time to see if it would also show trends for the states and the country. Read Full Article →