The Atlantic Cities had an interesting piece about a website that highlights some really great Census charts from the 1800's. The site by Jonathan Soma is called A Handsome Atlas.
Soma unearthed the Atlases by chance. While researching the spread of Chinatowns in New York City, he discovered a trove of maps and charts in a musty backroom of the Library of Congress web site. "Originally I was hoping to do some data visualizations with really old census stuff," he says. "But then I stumbled upon all of these amazing ones that had already been done."