Today Kirtsy.com posted a selection of photos taken by Charles W. Cushman. He donated over 14,500 photographs taken on Kodachrome slide film between 1938 and 1960 to Indiana University and the entire (at least it seems like the entire) collection is browse-able online.
The photos are so clear and colorful. There are genre headings, like Night Photos, where I found the above photo of San Francisco taken on July 4, 1940.
And subject headings like dirt roads, where I found the above: a corn field in Indiana in 1938.
If you have a couple minutes, or a couple hours, to kill online, I highly recommend taking a look.