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!
From Philadelphia (In 6 layers) Depicts: 1897
|1897||41 minutes ago.||4 control points.|
Philadelphia and vicinity / In top left margin: U.S. Geological Survey. Charles D. Walcott, director.
From Philadelphia (In 6 layers) Depicts: 1896
|1896||about 1 hour ago.||4 control points.|
Smith's map of the city of Philadelphia / "Entered according to act of Congress in the year 1887 by J.L. Smith."
From Philadelphia (In 6 layers) Depicts: 1887
|1887||about 2 hours ago.||4 control points.|