Historic plaque about the <a href="https://en.wikipedia.org/wiki/Aberdeen_Proving_Ground" class="extiw" title="w:Aberdeen Proving Ground">Aberdeen Proving Ground</a> on the median of <a href="https://en.wikipedia.org/wiki/U.S._Route_40" class="extiw" title="w:U.S. Route 40">U.S. Route 40</a> in <a href="https://en.wikipedia.org/wiki/Aberdeen,_Maryland" class="extiw" title="w:Aberdeen, Maryland">Aberdeen, Maryland</a>.
<a href="//commons.wikimedia.org/wiki/User:DanTD" title="User:DanTD">DanTD</a>
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>