This experience added invaluable engineering experience to his architectural expertise .
At the outset of the American Civil War , Withers volunteered and received a commission as a lieutenant in the 1st New York Volunteer Engineer Regiment .
This experience added invaluable engineering experience to Withers ' architectural expertise .
At the outset of the American Civil War , Withers volunteered and received a commission as a lieutenant in the 1st New York Volunteer Engineer Regiment .