A tip o' the hat to Popehat for bringing this to my attention.
The Library of Congress has released over 1,500 color photographs of the late 1930's and early 1940's showing the tail-end of the New Deal and the beginning years of World War II. They're meticulously catalogued and sorted, and show the USA in that period in a whole new light (to those of us who never knew it at first hand). I'm sure many older folks who can remember those years will be fascinated to view them.
Since all the photographs are (by definition) in the public domain, I've selected four at random that caught my eye, to give you a foretaste of what you'll find at the link above. I can see I'm going to spend many happy hours browsing through the collection (and the more than 170,000 black-and-white photographs linked from that page). The originals at the link can be viewed in larger scale than I've reproduced them here - click on the thumbnail view to see a larger version, then click on the 'All Sizes' icon at the top of the larger picture for a full-size view.
There are hundreds more photographs at the link. Highly recommended viewing.