Line of sight — Gettysburg

University of Maine professor of history Anne Knowles uses GIS (Geographic Information Systems) to explore and illustrate how the Civil War disaster at Gettysburg could have been a result of the geography as seen from General Lee’s vantage point.


Anne Knowles:
Gettysburg is another subject that so many people have studied. It is the most written about event in human history, many say.

I realized, as a historical geographer, that no one had actually asked the question what could Gen. Lee see at the battle. Because, of course, what commanders can see immediately helps shape their command decisions.

We used a GIS method called viewshed analysis. My team and I — I always work in a team — to put ourselves in Gen. Lee’s boots in the cupola of the Lutheran Seminary and look out over the digital landscape that we had created.

Which then reveals what parts of the landscape are in shadow that he cannot see, and what parts were exposed to his vision.

What we believe that landscape analysis showed was that he was unaware of how many Union forces were massing, coming up from Washington, D.C., in defense of Gen. Meade’s position.

When Lee launched the famous attack, Pickett’s Charge, on day three, he really didn’t know what he was running into. We think that helps explain the disaster on that day for the Confederates.