The David Rumsey Collection was started nearly 20 years ago, and focuses primarily on cartography of the Americas from the 18th and 19th centuries. The collection includes atlases, globes, school geographies, books, maritime charts, and a variety of separate maps, including pocket, wall, children's and manuscript. Materials that were created in America and that illustrate the evolution of the country's history, culture, and population distinguish the collection. Close inspection of the maps often reveals the rise and fall of towns, mining excavations, the unfolding of the railroads, and the discovery" of the American West by European explorers. The collection also includes European imprints containing maps of the Americas that were influential to American cartographers, as well as maps of other parts of the world distinguished by great craftsmanship, significance and beauty. [...] Multiple maps from different time periods can be viewed side-by-side. Or, the end user can create their own collection of maps by saving groups of images that hold particular interest. Complete cataloging data accompanies every image, allowing for in-depth searches of the collection. [...] The digitized maps are very high resolution images scanned at at least 300 pixels per inch. The larger maps generate files frequently approaching two gigabytes in size; the average file size of images in the collection is 100 megabytes." [Self-description]