McKeldin's most extensive collection of historical U.S. maps is 27,000 sheet maps extracted from the Congressional Serial Set, a massive compilation of official U.S. Government documents and reports that chronicle the growth and development of the U.S. from the early 1800's through the 1950's.
Among the dozens of subjects depicted by these maps: public land surveys; exploration and territorial expansion; Indian affairs; hydrography and navigation; fisheries and agriculture; geology and hydrology; population and demographics; weather and climate; foreign and military affairs; boundary and land claims; urban development.
