Middle Ground.

The statistical center of the United States moved a little south and a little west in 2010. It was ever thus.

The mean center of population is determined by the Census Bureau. It's the point where a map would balance if everybody in the country weighed the same. I live about 100 miles from that point.

In 1870 the center was in Highland county, Ohio. That was just about the time my people left that area. They went west but, contrarily, a little north. The map in this Wikipedia entry is cool. This migration looks like an Interstate highway.