Now all roads lead to France and heavy is the treadOf the living; but the dead returning lightly dance.
Virginia War Museum in Newport News, Virginia has a nice collection of World War I posters
The period from about 1890 or so until 1945 is really the golden age of posters. I've put a couple of pages up on my blog for WWI and WWII posters, as well as Great Depression posters. This selection of German posters is really a nice one and I'm going post a thread on mine linking yours in. Poster art has really died off. I suppose television and other media really did it in.