Rosaryville State Park

Mount Airy Mansion

Signage detailing history of Rosaryville State Park

Beautiful Mount Airy Mansion is located in the heart of Upper Marlboro's hunt country and is one of the oldest Maryland mansions connected to the Calvert family, the Lords Proprietor of colonial Maryland. Some historians speculate that parts of the building may date from the 1670s and served as a hunting lodge for the Lords Baltimore. However, a 1752 edition of the Maryland Gazette makes clear that whatever was there burned to the ground in that year. Benedict Swingate Calvert, the property owner at the time, probably built the east wing of the present structure shortly thereafter to replace the lost structure. Over the years, as the property descended through the Calvert family, the structure was enlarged to its modern proportions. The west wing is a fine example of the Greek Revival style of architecture that was popular in the early 19th century.

George Washington attended the 1774 marriage of his adopted son, John Park Custis, to Eleanor Calvert at Mount Airy.

Reenactors at Rosaryville State Park

In 1902, the property left the Calvert family, being purchased by Matilda ("Tilly") Duvall, who renamed it Dower House and operated a country inn here. Another fire in 1931 left only the masonry walls standing. Eleanor Medill ("Cissy") Patterson, publisher of the Washington Times-Herald and a prominent hostess of the era, purchased the ruins and restored them to their former glory. Ms. Patterson entertained presidents, ambassadors, authors and other prominent guests at Mt. Airy.

"Cissy" Patterson bequeathed the property to Ann Bowie Smith in 1948. In 1973, the State of Maryland purchased Mt. Airy, with state and federal funds, from the Smith family and made it part of Rosaryville State Park. It now serves again as a site for gracious entertainment.

Parties, great and small, weddings, births, deaths and visits from seven presidents have left their marks, leaving a wonderful feeling of expectancy to the lovely old home. Visitors can experience the history and atmosphere of Mount Airy. 

The entrance to Rosaryville Road is accessible by hiking, biking, or equestrian only.

Mount Airy Mansion
9640 Rosaryville Road
Upper Marlboro, MD 20772​