U. S. Map Shows which Ancestries Make up that County
From The Washington Post, April 18, 2014. "The history of European colonization of the Americas is still evident today in most of the United States. This very cool map shows which ancestries make up the largest population in each of the country’s 3,144 counties."
Another map showing the population growth and decline, changes in racial and ethnic concentrations and patterns of housing development appeared in the The New York Times and you can click on every county to get the above information.
Census Bureau; socialexplorer.com
