http://www1.coe.neu.edu/~dan/z-ns-start/showtime2.html
1880s-1890s TOBACCO INSERT CARDS - - - Early 1900s A.T.C. and B.A.T.
start here with Allen and Ginter :-)
there are also "albums" and "banners" that bring it all together. I'm partial to 19th century stuff - the lithography and artistry quite spectacular. Your category might include exhibits, bread cards, arm and hammer - the list goes on and ..........