Maps are some of the coolest things ever made. Think of all the great information on a map and how much humans have depended on particular maps to create history. How did our ancestors migrate across the globe and across the country by using contemporary maps? How has the same landscape changed over time? You can follow a lot of that stuff at USGS. See below.
Historical Topographic Maps - Preserving the Past
In 2009, USGS began the release of a new generation of topographic maps in electronic form, and is now complementing them with the release of high-resolution scans of more than 178,000 historical topographic maps of the United States.
Historic maps are snapshots of the nation's physical and cultural features at a particular time. Maps of the same area can show how an area looked before development and provide a detailed view of changes over time.
The goal of The National Map's Historical Topographic Map Collection (HTMC) is to scan all the USGS historic topographic maps published by the USGS since the inception of the topographic mapping program in 1884.
The Historical Topographic Map Collection (HTMC) exists online as a digital collection at http://nationalmap.gov/historical/ and as a physical paper collection of maps in the USGS Clarence King Library in Reston, Virginia.