New York Public Library Map Warper and David Rumsey Map Collection

Searching old maps is sometimes the only way to understand historical references to places. It is one thing to say that your ancestors lived in a certain place. It is an entirely different thing to understand what living in that place meant in the context of their family history. I have run into this type of situation many times when I am trying to separate out individuals with the same surname and either include them in or exclude them from family groups.

Some time ago, Google Earth began to include a few selected Maps from the David Rumsey Map Collection using a map viewing program. Here is the explanation of the process and the maps that are available from the link referenced:

The over 120 historical maps in the Google Maps have been selected by David Rumsey from his collection of more than 150,000 historical maps; in addition, there are a few maps from collections with which he collaborates. These maps can also be seen in the Gallery layer of Google Earth, Rumsey Historical Maps layer, and in the Google Earth viewers on this website.

All the maps contain rich information about the past and represent a sampling of time periods (1680 to 1930), scales, and cartographic art, resulting in visual history stories that only old maps can tell. Each map has been georeferenced, thus creating unique digital map images that allow the old maps to appear in their correct places on the modern globe.

Some of the maps fit perfectly in their modern spaces, while others (generally earlier period maps) reveal interesting geographical misconceptions of their time and therefore have to be more distorted to fit properly in Google Maps and Earth. Cultural features on the maps can be compared to the modern satellite views using the slider bars to adjust transparency.

If one of the 120 happens to be a map you are interested in viewing, then this is a useful tool. But there is another option. The New York Public Library has a Map Warper as shown in the video above. As described in the website:

The NYPL Map Warper is a tool for digitally aligning ("rectifying") historical maps from the NYPL's collections to match today's precise maps. Visitors can browse already rectified maps or assist the NYPL by aligning a map. Play the video above to tour the site and learn how to rectify a map yourself.

Everyone is welcome to participate!

If you are working with old maps (and we all should be) then you need to be aware of this tool.