Many of the most heavily used historical collections in the Geography and Map Division are available online. Much more, however, are available for viewing on site in the Geography and Map Reading Room. Researchers are encouraged to consult with the division's reference staff for assistance. The staff of the Geography and Map Division provides skilled reference service that is facilitated by catalogs, bibliographies, inventories, and other finding aids. Patrons are encouraged to examine the original materials in the Geography and Map Reading Room, the research center dedicated to serving the division's collections.
Scanned map images make use of special features such as location key maps, indexing systems, and “zoom” capabilities. The compression technology does not eliminate any of the pixels of the original, making it possible for users to enlarge portions of the maps in order to see detail that is invisible to the naked eye on the original item. The navigator window outlines the portion of the map that is included in the enlarged image.
Most maps acquired since 1968 have been made available in the catalog which are searchable by geographic area, title, author, and subject, as well as by call number in the Library of Congress Online Catalog. Catalog records for current acquisitions continue to be added to the automated system. This is a good place to begin a research project as you can do your initial searching in the Library's online catalog before visiting the Geography and Map Division. Though representing only a small portion of the total cartographic resources of the Library, maps searchable online represent a good cross-section of the Geography and Map Division's complete holdings, particularly Americana. Online cataloging records may lead you to other cartographic material for a given place and time period. The full cataloging record for a particular map may also include contents notes that describe some of the information shown on the item.
Searches for cartographic materials can be limited by location in the Library to "Geography & Map" and by type of material to either "Map" or "Map (manuscript)," as well as by language and place of publication. Portions of all the following categories of maps can be found among the cataloged maps.
Many items of great interest to historians are among the approximately 1.5 million maps in the Single Map Collection, which includes both cataloged and uncatalogued material. Many of the maps received in the Geography and Map Division before the advent of machine-readable cataloging in 1968 are not cataloged, maps which are also known as being part of the Title Collection. For example, historians will find cartographic sources filed under “North America,” “United States,” and the names of regions, individual states, and administrative units such as counties and cities. The holdings are frequently further subdivided by subject. In addition, there may be several possible filing locations for identical copies of the same item or very similar items, and a variety of additional filing locations for closely related items. Research projects that focus on a particular geographic or political unit such as a state, county, or city are most easily supported by cartographic material.
It is important to remember that the quality and quantity of cartographic information that is available vary considerably over place and time. Although rich resources may exist for some locations, other areas—particularly less affluent rural communities—may not be as well represented in the collections simply because fewer maps were made of these places or fewer maps were collected and preserved.
The Single Map Collection includes a wide range of geographic and cartographic products. Some of the maps are atlas plates or maps that originally were included in monographs or serials but have been removed from their bindings. A significant and often overlooked category of material found in this collection are photo reproduced copies or facsimiles of material held by other repositories either in the United States or abroad. Also included are many maps that came to the Library through copyright deposit prior to the 1970s.
Access to this collection, which includes some of the division's most heavily used material, is facilitated by many published finding aids and bibliographies. Materials related to the American Revolutionary War era, the Civil War, county landownership, railroads, panoramic maps, literary maps, and maps showing Spanish exploration and settlement in North America, are listed and described in excellent bibliographies that are widely available in university and large public libraries.
A vast amount of cartographic information awaits discovery and analysis by diligent researchers. Access to this collection, which includes some of the division's most heavily used material, is facilitated by many published finding aids and bibliographies. For the most part, however, using the portions of the single map collection not covered by published bibliographies requires the assistance of highly trained reference and specialist staff members who are experienced in locating specific kinds of resource material for researchers. Frequently, the staff can suggest items that are particularly useful for specific studies. Reference questions can be directed by patrons to the Division through the Ask A Librarian page or a visit to the reading room in order to determine what material best serves their needs.
Set Maps contain at least ten sheets published at a uniform size, usually drawn at the same scale, that are intended to be portions of a larger map. In general, these maps are medium to large scale and provide much more detailed information than is shown on single maps. Many of the set maps are controlled by index maps that indicate which sheets the Library holds for a given series.
Some of the most heavily used maps in this part of the collection are the large-scale topographic maps of the Austro-Hungarian Empire dated circa 1870 to 1914 (G6480 s75.A8). These maps are frequently used to locate villages and towns that were the homelands of large numbers of Jewish immigrants who came to the United States around the turn of the twentieth century or towns that were “lost” in the Holocaust. Similar sets exist for other countries of origin for American immigrants (e.g., for Italian immigrants, G6710 s100.I8). Detailed set maps for the United States as a whole, as well as for individual states, are also available.
Most of the Atlas Collection is cataloged, with its records available online and searchable in the Library of Congress Online Catalog. The catalog can be searched by geographic area, title, author, and subject. In addition, there are detailed finding aids available for much of the collection, including the nine-volume reference work A List of Geographical Atlases in the Library of Congress by Philip Lee Phillips and Clara Egli LeGear, which contains a partial index to individual plates bound into atlases published before 1968.
The division's rare globes, atlases, and maps, including all manuscript maps, are housed separately in a secure facility. Most of this "Vault" collection has been cataloged, save for a few maps that are filed under their appropriate LC call number but whose records are unverified and therefore not included in the LC catalog. Reading Room staff are able to confirm the status of Vault materials and retrieve them for use.
Special requirements may apply to use and reproduce. A considerable portion of this material has been cataloged and can be searched online. There are also many alternative and supplementary finding aids for special collections such as the preliminary, unpublished vault shelf list and unpublished inventories and indexes that are available for use in the division reading room.
The division maintains a collection of approximately eight thousand books in its Reference Collection related to geography and cartography. In addition to full-length monographs on maps and mapmakers, there is a pamphlet file of articles about specific items in the collections written by division staff members or scholars studying the Library's maps and atlases. An extensive collection of unpublished inventories and indexes is also available.
The reference collection contains basic works on the subjects of history, geography, and cartography; catalogs related to other major map collections and exhibitions; and two major bibliographies that are particularly helpful for historical researchers. The Index to Maps in Books and Periodicals by the American Geographical Society, Map Department provides access to materials that may be found in other special format divisions of the Library of Congress and in the General Collections. It also gives publication information about individual items housed in the division that may have been removed from other works. The U.S. Serial Set Index and Cartobibliography of Maps, part 14, by Donna P. Koepp lists the maps that are found in the Congressional Serial Set that were originally published by the U.S. Senate and House of Representatives as part of official reports.
Another resource is The Bibliography of Cartography published by the Library of Congress, Geography and Map Division, in five volumes and its First Supplement, in two volumes published in 1980. This finding aid includes articles about cartography published in a variety of periodicals, listed by author and title. It includes subject headings. More recent articles have been indexed and are in card form, available for use in the division. Its usefulness in finding material about women mapmakers and geographers is considerable if the name of the author writing articles about women is known.
A small collection of place-name literature describing how specific locations have come to be named is also included in the division's reference collection. Most of the place-names in the United States have been designated by explorers, early settlers, surveyors, mapmakers, and government officials. Some of these names honor wives, sisters, daughters, or sweethearts who can be identified by using this material. Such works are generally devoted to a single state, although occasionally a volume pertains to a larger geographic area or to certain kinds of names, such as those related to Native Americans. Except for a few items in the pamphlet file, place-name literature is fully cataloged and can be found under the name of the state.