American Memory, "American Variety Stage: Vaudeville and Popular Entertainment, 1870-1920."
http://memory.loc.gov/ammem/vshtml/vshome.html
Vaudeville may have disappeared as a popular venue long ago, but it remains alive, through the Library of Congress's holdings, on this site filled with playbills, programs, sound recordings, film clips, scripts, photographs and memorabilia from a once vibrant art.
Referenced in:
Pennsylvania Show Business