Marietta was the plantation home of Gabriel Duvall. He undertook the building of this modest Federal style brick house at about the same time he was appointed an Associate Justice of the United States Supreme Court in 1811, a position he held for twenty-three years. Only the Judge's law office and root cellar remain of the many outbuildings that originally supported the 650 acre estate. In the early 1830s, when Duvall became guardian to his grandchildren, a two story addition was built.

Tour an early 1800's home with many original features including a summer kitchen. A one-room museum holds memorabilia from Middletown and surrounding areas and a Genealogy Library is available for research.

A fine example of Georgian architecture, popular in Maryland in the late 1700's, Montpelier Mansion sits on approximately 70 acres of beautiful parkland. Architectural and building construction details, as well as historical research, suggest that the house was constructed between 1781 and 1785. Major Thomas Snowden and his wife Anne, original owners of Montpelier Mansion, welcomed many distinguished guests into their home including George Washington and Abigail Adams.