GUIDE: Evans, Charles. American bibliography. National index of American imprints through 1800. Z1215.E923A5 The Center owns only the monographs in the set. It includes approximately 42,000 books, pamphlets and broadsides published in the United States from 1639 through 1800. The titles in the set have not been analyzed by the Center, but can be verified in the bibliographies upon which it is based.