The Smithsonian Institution Building provided a bird's eye view of the Civil War from 1861 to 1865. The Castle's towers provided a clear view across to battles in Virginia and Maryland. Union soldiers drilled on the grounds surrounding the Institution. And the influx of soldiers and citizens to the nation's capital increased the number of visitors to the Smithsonian's exhibits and programs. These images show how remote the Castle was from downtown Washington and how close it was to nearby Confederate Virginia.