County map of Texas; Galveston Bay and vicinity inset. From The Lionel Pincus & Princess Firyal Map Division, NYPL
Finally, you don't have to raise your voice over a group of whisperers in the New York Public Library to get a better view of its map collection. Actually, you don't even need to visit the place at all. Over 20,000 maps and cartographic works from the NYPL's Lionel Pincus & Princess Firyal Map Division have been uploaded and made downloadable for the public.
Map of the city of New York. Courtesy NYPL.
"We believe these maps have no known US copyright restrictions," explains a blog post announcing the wholesale release of the library's map collection. "It means you can have the maps, all of them if you want, for free, in high resolution. We’ve scanned them to enable their use in the broadest possible ways by the largest number of people." The NYPL is distributing the maps under Creative Commons CC0 1.0 Universal Public Domain Dedication, which means you can do whatever you want with the maps.
A chart of the West Indies from Cape Cod to River Oronoque. Courtesy NYPL.
Combined with its existing historical GIS program, the NYPL wants its users to engage with the maps, and allows them to warp (fitting together based on corresponding anchor points) and overlay the historic maps with modern geoweb services like Google and Open Street Map. Users can export WMS, KML files, and high-quality TIFFs. The historic map appears side by side with the modern maps, and users are invited to mark corresponding points on each, so you can overlay the historic map over the current day's.
County map of Texas ; Galveston Bay and vicinity inset overlaying Open Street Map. Courtesy NYPL.
Although you don't really have to cite where you found the maps, it'd be nice, says the library's blog post, if maps accessed from the collection credit NYPL thusly: "From The Lionel Pincus & Princess Firyal Map Division, The New York Public Library.” This helps the library Google itself and track usage of the maps in future city planning projects, art, films and other experiments.
Map of the western part of Asia Minor overlaying OSM. GIF by the author, Courtesy NYPL.
Sure, a great amount of these maps are New York City fire insurance atlases from the mid-19th to mid-20th century, but the collection also includes "over a thousand maps of Mid-Atlantic United States and cities from the 16th to 19th centuries; over 700 topographic maps of the Austro-Hungarian empire created between 1877 and 1914, a collection of 2,800 maps from state, county and city atlases, and more than 1,000 maps of New York City, its boroughs and neighborhoods." For the historic cartographile, Christmas may have come late, but here it is.