This is a great collection for U.S. history presentations on development of the railroads, or on settlement of the west, in particular.
The Railroad maps represent an important historical record, illustrating the growth of travel and settlement as well as the development of industry and agriculture in the United States. They depict the development of cartographic style and technique, highlighting the achievement of early railroaders. Included in the collection are progress report surveys for individual lines, official government surveys, promotional maps, maps showing land grants and rights-of-way, and route guides published by commercial firms.
Heck, if nothing else, these make great backgrounds for PowerPoint presentations.
Bookmark the site — kids working on projects specific to a state or region should have a field day with these things.