Many people want maps that show an area of the United States as it existed many years ago. These are called historical maps, and there are two types.
The most common type consists of special maps prepared by commercial firms to show such historical features as battle-fields, military routes, or the paths taken by famous travelers. Typically, these maps are for sale to tourists at the sites of historical events.
The other type is the truly old map--one compiled by a surveyor or cartographer many years ago. Lewis and Clark, for example, made maps of their journeys into the Northwest Territories in 1803-6, and originals of some of these maps still exist.