The William Martin Armistead House is a historic building at 1510 Hyde Park Street in Sarasota, Florida, United States. It was owned by William Martin Armistead who was prominent in the advertising industry. On March 30, 2009, it was added to the U.S. National Register of Historic Places.
The William Martin Armistead House wasn't considered Historic until 2009.
Just because it wasn't added until 2009 doesn't mean it wasn't considered historic until then. System assumes date it was official is same as when it was considered historic.