The Library Company is one of the premier centers for the study of the history of printing and publishing in America to about 1880. The most important resources for research in this area are the printed materials themselves, not only for the information contained in their texts but also for what can be learned from their physical features, such as bindings, inscriptions, paper, ink, owners’ marks, etc. The Library Company has the second largest collection anywhere of American imprints up to 1820, and it is among the top half dozen collections for the period 1820 to 1860. That alone would make the collection useful for book history research, but other resources are also available. First, the online catalog includes detailed physical descriptions of most of the older books, along with the capacity to search or to qualify searches by date of publication, publisher or printer, binder, illustrator, genre, physical characteristic, and former owners. This sort of cataloging is standard for rare book libraries, but the in-house database of 19th century binders and bookbinding designs and materials is a unique resource that will soon be available on our website. Second, the collection of bibliographies, book trade publications, and secondary current literature on American book history is the strongest in the region. Third, the staff is especially knowledgeable in this subject area, and some of them have done considerable research of their own. Fourth, the collection includes not only books that were published in America but also books that were imported from Britain and the Continent. The transatlantic trade in books was an essential part of American book culture, in the colonial period, when book imports exceeded native production, and in the early national period, when most American books were reprints of British books. Fifth, the collections include the libraries of such 18th-century intellectuals as James Logan, William Byrd of Westover, Benjamin Franklin, and Benjamin Rush, and those of 19th-century collectors such as the bibliophile William MacKenzie and the novelist and journalist Anne Hampton Brewster. Finally, the Historical Society of Pennsylvania next door happens to hold one of the largest collections in the country of papers of printers and publishers, including the papers of Mathew Carey and his successors, the most important publishers of the early national period. This is the largest business archive of any kind from that period. (The Library Company has the largest collection of imprints written by or published by Carey.) HSP also holds a vast collection of personal papers that exhaustively document early American writing and reading practices.