Digital Resource: New York Public Library Maps

As one of its ongoing digitization projects, the New York Public Library has placed over 20,000 maps on its website. Many of them are of direct interest to business historians. Slate's Rebecca Onion blogged about one example, "Chase's Ice Map" of several northeastern rivers in 1894, showing "location, capacity, ownership & cutting surface of the Kennebec, Penobscot & Hudson rivers."
   Other examples include:
"Map of the Oil District of West Virginia," 1864
"Plan of Land & Water Lots of the Charlestown Wharf Co.," 1838
"Map of French & English Grants on Lake Champlain," 1851
"Map & Profile of a Ship Canal from Richmond to Warwick," 1836
"Post Route Map of the State of Arkansas and of the Indian Territory," 1880
"Ontario (Villages) Business Notices," 1874
The maps are searchable by keyword and by several categories such as "Topic" and "Place." The library site has an excellent viewer, which allows users to zoom in on details at very high resolution. Most items are in the public domain.