New Philadelphia National Historical Park Act This bill establishes the New Philadelphia National Historical Park in Illinois as a unit of the National Park System. The purposes of the park are to protect, preserve, and interpret the historic resources associated with the town of New Philadelphia, the first town in the United States planned and legally registered by a free African American before the Civil War. The park shall consist of the approximately 124.33 acres of land within the boundary generally identified on the map titled New Philadelphia National Historic Site Proposed Boundary and dated July 2021.