It was listed on the National Register of Historic Places in 1970, and made a National Historic Landmark in 1989.<ref>[http://tps.cr.nps.gov/nhl/detail.cfm?ResourceId=1002&ResourceType=Building National Historic Landmark summary listing]</ref> | It was listed on the National Register of Historic Places in 1970, and made a National Historic Landmark in 1989.<ref>[http://tps.cr.nps.gov/nhl/detail.cfm?ResourceId=1002&ResourceType=Building National Historic Landmark summary listing]</ref> |