The National Register of Historic Places (NRHP) was authorized by the National Historic Preservation Act of 1966 under the National Park Service and is the country's official list of historic places worth preservation. Over 94,000 sites across the county were listed on the register as of April 2019. The Union Station Entrance was added to the register in 1974 and was removed in 1999. Below is an infographic with some interesting facts about the NRHP and Ohio.