“A spectacular historical atlas refashioned for the 21st century. Here you will find one of the greatest historical atlases: Charles O. Paullin and John K. Wright’s Atlas of the Historical Geography of the United States, first published in 1932. This digital edition reproduces all of the atlas’s nearly 700 maps. Many of these beautiful maps are enhanced here in ways impossible in print, animated to show change over time or made clickable to view the underlying data—remarkable maps produced eight decades ago with the functionality of the twenty-first century.” More information.

 
To cite the Atlas:Charles O. Paullin, Atlas of the Historical Geography of the United States, ed. John K. Wright. Washington, D.C.: Carnegie Institution, 1932. Digital edition edited by Robert K. Nelson et al., 2013. http://dsl.richmond.edu/historicalatlas/