Drawing on the Past: Enlivening the Study of Historical Geography at maps.nypl.org

By Matt Knutzen, Stephen A. Schwarzman Building, Map Division
February 3, 2010
Stephen A. Schwarzman Building

On behalf of The Lionel Pincus and Princess Firyal Map Division, the NYPL’s Director of Digital Strategy and Scholarship and our partners EntropyFree LLC, I am proud to announce the launch of maps.nypl.org

This new website is a parallel snapshot of all maps currently available on the Digital Gallery as well as a powerful set of tools designed to significantly enhance the way we access and use maps and the cartographic information they contain.

The first such enhancement is in how historic maps are viewed. The user interface of maps.nypl.org allows zooming and panning in a way that has come to be expected by users of web maps (Google Maps, Bing Maps etc...)
The next is georectification, which we are calling here “warping”, a familiar term to GIS professionals and few others. Map “warping” is the process where digital images of maps are stretched, placing the maps themselves into their geographic context, rendered either on the website or with tools such as Google Earth.
Illustrated here is the 1915 Redraft of the 1660 Castello Plan documenting early lower Manhattan, “warped” using the Map Warper and rendered in Google Earth.


And below here, a set of 98 detailed sheet maps of the New York City published by William Perris in the early 1850s, overlaid in Google Earth after having been “warped” and mosaicked using maps.nypl.org

Once historical map has been digitally “warped,” users of the Library’s digital maps can virtually “trace” features, such as cities, farm boundaries, rivers, ponds and even buildings, converting them into digital geospatial data. And that data, in turn can be easily linked to other digital information, such as building photographs, text citations or any other information that relates to the same geographic location.
Illustrated below is a photo of Phenix Bank at 45 Wall Street, digitally “pinned” to one of the maps in the series shown above.

One of the most exciting aspects of this project is its participatory nature, meaning that anybody with a computer can create an account, log in, and begin warping and tracing maps, whether for a school or personal project or otherwise. And when the project is complete, the contribution remains in place (à la Wikipedia and openstreetmap.org ), adding one more piece to this new historical geographic data model.
I’ll blog again about some of the ways maps.nypl.org is already being employed by a variety of user groups. Also, follow us on twitter for project updates and events.
For now, however, feel free to create an account, watch the how to video, and enjoy.