Use ephemera to add another dimension to your research. The online glossary from the Society of American Archivists defines ephemera as:
Ephemera: pl. n. (ephemeron, sing.) ~ Materials, usually printed documents, created for a specific, limited purpose, and generally designed to be discarded after use.
Notes: Examples of ephemera include advertisements, tickets, brochures, and receipts. A repository may collect ephemera as examples or specimens. Individuals often collect ephemera as mementos or souvenirs because of their association with some person, event, or subject; personal collections of ephemera are often kept in scrapbooks.
From The Glossary of Archival and Records Terminology by Richard Pearce-Moses, http://www.archivists.org/glossary/index.asp.
Tamiment's collections include some one million pamphlets, leaflets, flyers, manifestoes, reports, serials and other internal documents from a wide variety of labor and left organizations, many based in New York City. See the Printed Ephemera Collections Research Guide for tips of finding printed emphemera collections
The American Memory Collection of the Library of Congress is a vast resource for researchers seeking digitized texts, maps, manuscripts, motion pictures, sheet music, song sheets, photos, prints, sound recordings, books, and other printed texts, including ephemera.
Image: [Ten menus of the Lotos Club, New York April 30, 1892- Dec. 16, 1893.]..Printed Ephemera Collection; Portfolio 130, Folder 8.
American Broadsides and Ephemera is a subscription database from Readex available through NYU Libraries containing broadsides printed between 1820 and 1900 and ephemera printed between 1760 and 1900.
Image: "Now ready for delivery--to subscribers only. The first volume of the History of the city of Brooklyn, N.Y. By Henry R. Stiles, M.D." American Broadsides and Ephemera, Series 1, no. 12463