US Holocaust Memorial Museum Library - http://www.ushmm.org/research/library/ Resources for family history and other research as well as access to the online catalog.
The Library Company of Philadelphia - http://www.librarycompany.org/ Specializes in the history and background of American culture from the colonial period to the end of the nineteenth century; with an overview of the collection, access to the online catalog, and general information.
Help build the largest human-edited
directory on the web.