For which war was the ammunition plant, located in Illinois, and now a tallgrass prairie reserve; the largest conservation site in the Chicago Wilderness region, originally opened?
Midewin National Tallgrass Prairie: The Midewin National Tallgrass Prairie (MNTP) is a tallgrass prairie reserve and United States National Grassland operated by the United States Forest Service. Joliet Army Ammunition Plant:  Opened in 1940 during World War II, the facility consisted of the Elwood Ordnance Plant (EOP) and the Kankakee Ordnance Works (KNK).
i don't know