http://docsouth.unc.edu/index.html Documenting the American South. The Collections and Geographic Links (click on US map) are particularly helpful
http://www.thepeoplehistory.com/1930s.html The People History. A non-academic site that details “popular culture, music, film and TV, technology, world events, cost of living, inflation, price of goods and property, wages, and the value of money” from the decades of the 20th century