Illustration of what can be achieved warping historical maps

To engage the public with a fascinating resource of  new and old New York maps, the New York Public Library has made available a tool for digitally aligning historical maps to todays maps.

They have already rectified some of the maps in their collection but they wanted to enable and empower the public to be able to do it for themselves.

You can either select an already aligned map or choose your own maps to rectify.

    • The tool uses at least four control points on both maps which brings them into alignment so that you can see the changes in land use and development over time.
    • Once the historical map has been digitally warped, the user can then ‘virtually’ trace a place of particular interest, it might be a whole area in a city, a farm or even a building, converting it into geo spatial data.

This data in turn can be linked to other digital information such as photos or text that can then be pinned onto the map.

The ‘how to’ video’ on the library website is very helpful and easy to follow. You will need to login to use the resource but all the guidance is very good.

Try the video here



Once you have created your warped map it is left on open access for others to use.

This brilliant tool and the insight that the New York Public Library had, in realizing that to make their collections interactive and dynamic, they had to engage with the technology and empower the people.

This is exactly what public archives, museums and libraries should be doing, allowing as much access to data as possible in a way that turns data into information into knowledge and this we can all share and comment upon.


Map Warper is a tool for A brilliant resource for the public. Visit the New York Public Library site and be part of re-shaping geographical history

Sorry, comments are closed for this post.