I attended American University back in the mid-'90s. It was kind of mind-blowing to see buildings in the neighborhood routinely cordoned off with stern warnings that cleanup of chemical weapons detritus from the World War I days of "Camp American University" (https://en.wikipedia.org/wiki/Camp_American_University) were underway in them. It gave me a vivid sense for how the scars of war can linger for decades, even in places far away from the actual battlefronts.

There's a good article from an AU student publication about the government's wartime use of the campus here: http://www.amwordmag.com/article/2015/12/a-hidden-history

It taught me something even I hadn't heard before: that the campus student union building where I'd spent so many happy undergraduate days, Mary Graydon Center, was first constructed by the government as the "Chemical Warfare Service Building."