The primary pattern that jumps out is the large swaths of the country that experienced outright population declines. Appalachia, the Midwest, and the High Plains regions, along with a large chunk of the Mississippi Delta, all show predominantly significant population declines. Conversely, Florida, the Tucson-Las Vegas corridor, a corridor through central Utah and Colorado, and some major metropolitan areas in the East and Texas show significant population growth. The growth in the Washington, DC area is not surprising due to the massive growth in federal government (military and otherwise) programs.
Map source: Dr. William H. Frey