This map shows the predominant ancestry of every county in the country, based on data gathered in the 2000 US census.  As a measure of the prevalence and persistence of ancestral identification, the map is fascinating and surprising.

Many of us are invisible on this map: we are minorities within majorities.  In that sense, the map hides diversity rather than exposing it, but, even so, the level of diversity and homogeneity within the states is striking. Continue reading →