A little bit of nostalga here: There’s a Flickr set of illustrations from the Advanced Dungeons and Dragons coloring book, circa 1979
gallery
Vintage Photos of Moscow 1909
Here’s an interesting set of Flickr photos of pre Revolution Moscow.
Stereographic Photos of The Civil War
Here’s a Library of Congress page with scads of stereographic photos from the Civil War.
American Western Frontier Photos
For Wild West fans, here are a bunch of period photos of the American West.
Color Photos From The US In The 1930s and 1940s
Fans of pulp and other inter-war gaming might be interested in seeing these rare color photos of life in the US in the 1930s and 1940s. It should give you some good ideas about colors.