Census, Racial Types, and Time

The Pew Trust has a fascinating visualization of the complicated way in which Americans (and the American census in particular) classified people into racial categories:


The census years are aligned across the top, and the inclusion and evolution of categories is reflected in the horizontal colored bands.  Note that citizens could only choose their own racial categories in 1960. Before this, census enumerators would choose your race.

Thoughts or comments on this post?