I remembered driving by this house years ago and being told that it was used as a hospital back in the Civil War. I know that it's in this neighborhood not far off Powhatan Street (in the area of Virginia Ave. and Nottingham St.). It's on a good sized peice of property with a small barn and shacks torward the rear. Any idea of the address or the street it's on? Here's the general area that it's on, hopefully it helps.
http://maps.google.com/maps?hl=en&q=%22N+Rockingham+St%22+%2B+%22Arlington,+VA%22&oe=UTF-8&um=1&ie=UTF-8&sa=N&tab=wl&oi=property_suggestions&resnum=0&ct=property-revision&cd=1