"The Geography and Map Division of the Library of Congress holds more than 4.5 million items, of which Map Collections represents only a small fraction, those that have been converted to digital form. The focus of Map Collections is Americana and Cartographic Treasures of the Library of Congress. These images were created from maps and atlases and, in general, are restricted to items that are not covered by copyright protection. Map Collections is organized according to seven major categories. Because a map will be assigned to only one category, unless it is part of more than one core collection, searching Map Collections at this level will provide the most complete results since the indexes for all categories are searched simultaneously."