From the record
“The Frank Lloyd Wright/Prairie School of Architecture Historic District is located in the village of Oak Park in Cook County, Illinois, United States. The Frank Lloyd Wright Historic District is both a federally designated historic district listed on the U.S.”
Wikipedia article Frank Lloyd Wright-Prairie School of Architecture Historic District, CC BY-SA 4.0.
One of 621 National Register listings published here for Cook County · listed in 1973 · category: District.
Sources: the Wikipedia article · the case file at the National Archives · the National Register database, National Park Service


