Monday, May 30, 2016

USGS Historical Topographic Map Explorer

Gettysburg, Pa. results from the USGS Historical Topographic Map Explorer

Here is a nice resource for tackling pesky topographic puzzles:  the Historical Topographic Map Explorer, a convenient tool provided by the U.S. Geological Survey (USGS).  The available quadrangles reach back as far as the 1880's. Though these old maps postdate the Civil War by a few decades, I've found them useful in pursuing questions about 19th century road networks and terrain.  In the past though, the vintage surveys have been difficult or impossible to locate online. This tool, launched in 2014, now makes it easy to find all available maps with just a few clicks. Its usability is excellent.  Just search for the location you need, click a city name on the modern map, and the site automatically generates a timeline of all the available maps for the area that you can view and download.  I've included a screen shot for a search of "Gettysburg" at the top of this post.  Here are a few more images from the site:

New Bern, N.C. (USGS, 1901)

Petersburg, Va. (USGS, 1894)

Fredericksburg, Va. (USGS, 1889)