Geographic and Historical Maps

The Newbury Collection - 100 of thousands of maps showing county boundaries as well as local histories, etc

US Department of the Interior and Land Management -  The official Land Records Office for the USA

David Rumsey Collection of Maps - A huge collection of old and obscure maps from around the world

Gazetteer of British Place Names -  The definitive source from British place names, both historical and current and the current and historical county they were in.

Historical Map Works is a site where you can buy old maps related to your research.

HistoryGeo $ - links old maps to your research in an interactive map format for over 30 USA states.

Meyers Gazetteer - Images are from David Rumsey's collection.  Easy search engine.

US Geological survey site goes far beyond mapping.  Scroll down to find the section you want.

Arcanum Maps$  - Europe in the 19th Century