This paper was prepared originally for the Conference on the National Archives and Research in Historical Geography, November 8-9, 1971.

Genealogical research in U.S. censuses begins with identifying correct county jurisdictions ??o assist in this identification, the map Guide shows all U.S. county boundaries from 1790 to 1920. On each of the nearly 400 maps the old county lines are superimposed over the modern ones to highlight the boundary changes at ten-year intervals. Accompanying each map are explanations of boundary changes, notes about the census, & tocality finding keys. In addition, there are inset maps which clarify ??erritorial lines, a state-by-state bibliography of sources, & an appendix outlining pitfalls in mapping county boundaries. Finally, there is an index which lists all present day counties, plus nearly all defunct counties or counties later renamed-the most complete list of American counties ever published.

Genealogists and other historical researchers have valued the first two editions of this work, often referred to as the genealogist's bible."" The new edition continues that tradition. Intended as a handbook and a guide to selecting, locating, and using appropriate primary and secondary resources, The Source also functions as an instructional tool for novice genealogists and a refresher course for experienced researchers. More than 30 experts in this field--genealogists, historians, librarians, and archivists--prepared the 20 signed chapters, which are well written, easy to read, and include many helpful hints for getting the most out of whatever information is acquired. Each chapter ends with an extensive bibliography and is further enriched by tables, black-and-white illustrations, and examples of documents. Eight appendixes include the expected contact information for groups and institutions that persons studying genealogy and history need to find. ""

This catalog lists the 1910 population census schedules held by the National Archives and Records Service.