United States

Geographic Names Information System
The Geographic Names Information System (GNIS), developed by the USGS in cooperation with the U.S. Board on Geographic Names (BGN), contains information about almost 2 million physical and cultural geographic features in the United States. This site is searchable.

Library of Congress Maps: 1500 - 2004
Searchable database of maps housed in the Library of Congress' collection. This site specializes in "Americana and Cartographic Treasures ."

Perry-Castañeda, United States Maps
Excellent site with links to maps of all fifty states as well as historical, topographic, census, and other types of maps of the United States.