Online collection
DATABASE OF AMERICAN LABOR GRAPHICS AND SIDEWALK CONTRACTOR STAMPS
Two projects of Lincoln Cushing (lcushing@library.berkeley.edu):
The first at
www.lib.berkeley.edu/~lcushing/LaborGraphicsProject.html
tries to identify labor graphic collections -- graphics, prints, posters depicting workers, labor organizations, labor culture etc. The second at
www.lib.berkeley.edu/~lcushing/Stamps/SidewalkStampHome.html
is the documentation, cataloging and publication of symbols known as contractor stamps. - that recorded construction dates. These were symbolic of the pride that tradesmen and women displayed in building our country. Anyone who can contribute to this data bases is encouraged to contact Lincoln.