The foundation for this work is Koheleth America (KA), the standard bibliography of pre-1927 American Hebrew imprints and have thus included almost all the items it lists. Having decided to inspect all the books catalogued rather than rely on previous bibliographic works, works in KA that could not be located have been omitted. Books that were difficult to access were included only if a photocopy could be obtained. A few volumes that are no longer extant were catalogued from microfilms. The initial decision to follow KA accounts for the inclusion of a few works with little or no Hebrew text, as well as a few printed in Europe or the Land of Israel. Also later editions were catalogued only if they appear in KA. A special effort was also made to catalogue additional Hebrew books printed in North America prior to 1927 that do not appear in KA, partcularly volumes of rabbinics, derash and Americana. The following items were generally excluded from this expanded search: Haggadot, prayer books, educational works, and book catalogues; such items are included only if they appear in KA. The first calendar, periodical and derash are included even though these volumes contain little Hebrew text because they are the first publications of their genres. The first Hebrew calendar is catalogued, but later ones are omitted, as are all unfolded broadsides - p. xix.