The Geography and Map Division of the Library of Congress is the "largest and most comprehensive cartographic collection in the world, numbering over 5.2 million maps, including 80,000 atlases, 6,000 reference works, numerous globes and three-dimensional plastic relief models, and a large number of cartographic materials in other formats, including electronic." Many have been converted to digital form.

The focus of digital 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.

One of my favorite collections at the LOC Map Collections site is the panoramic map collection. The panoramic map was a popular cartographic form used to depict U.S. and Canadian cities and towns during the late nineteenth and early twentieth centuries. These maps are also known as bird's-eye views, perspective maps, and aero views.

Panoramic maps are nonphotographic representations of cities portrayed as if viewed from above at an oblique angle. Although not generally drawn to scale, they show street patterns, individual buildings, and major landscape features in perspective.