At the end of April 1868, uniform rows of white-washed wooden headboards, each representing a gravesite of a fallen Civil War service member, filled the hills of Arlington National Cemetery. The property’s prominent ridgeline, marked by the Arlington House, offered stunning views of Washington, D.C. Little else distinguished this national cemetery as remarkable. While it contained the graves of some 16,000 individuals and spanned 200 acres, Arlington was only one of approximately 74 national cemeteries established beginning in 1862, during the Civil War.