Known to art librarians as Lancour, after the librarian at the Cooper-Union who compiled the volume, Harold Lancour's American Art Auction Catalogues 1785-1942 is a union list of auction sales of art objects. Like Fritz Lugt's Répertoire... this volume is an integral part of provenance research. Sales are arranged by year, with entries following the manner set forth in American Book Auction Catalogues, 1713-1934, by McKay. Any catalogue that contained 25 or more art objects is included, allowing greater coverage of early estate sales. Following each listing, the extant copies of the aforementioned catalogue are provided. Our copy of Lancour is annotated with a carrot mark to indicate which catalogues we maintain in our collection. Of particular interest is the listing of auction houses, prefacing the sales. All known addresses and relevant dates are included, providing a unique list of galleries and auction houses unavailable elsewhere. Lancour is shelved in the library's reference collection at Z5939.A1 L3.