Oak Woods Cemetery was established on February 12, 1853; it covers an area of 74 hectares (183 acres) and is located at 1035 E. 67th Street in the Greater Grand Crossing area of Chicago's South Side. The first burials took place in 1860. Soon after the American Civil War, several thousand Confederate soldiers, prisoners who died at Camp Douglas, were buried here. A monument says that 6,000 soldiers were buried here and lists names of more than 4,000.
These bodies had originally been buried at City Cemetery but were exhumed and reinterred together in a mass grave, which came to be known as Confederate Mound, reported to be the largest mass grave in the Western Hemisphere.(Wikipedia)