Originally built in 1744 and enlarged in the 1760's, this Georgian-style house was the home of Phillip Key, uncle of Francis Scott Key, author of the Star Spangled Banner. Unusual features of the house are the inset portico, the main hall's hanging staircase, and a "triple fireplace" in the kitchen. Maryland War of 1812 site. Tudor Hall serves as the research library for the St. Mary's County Historical Society. Bookstore. The Research Center is open Thursday and Friday, 11:00 a.m. - 4:00 m. and on 2nd and 4th Saturdays, by appointment only. Call ahead for hours.