Rosaryville State Park
|Rosaryville State Park|
|Maryland State Park|
|Elevation||161 ft (49 m) |
|Area||1,039 acres (420 ha) |
|Management||Maryland Department of Natural Resources|
|IUCN category||V - Protected Landscape/Seascape|
|Website: Rosaryville State Park|
Rosaryville State Park is a Maryland state park in Rosaryville, three miles southeast of the Joint Base Andrews Naval Air Facility (formerly Andrews Air Force Base) in Prince George's County. The park includes the restored Mount Airy Mansion, which is operated as an event facility, as well as hiking, biking and equestrian trails for day-use. 
The Calvert family
Benedict Swingate Calvert, (c.1730-1788), son of Charles Calvert, 5th Baron Baltimore, lived at Mount Airy, and died there on January 9, 1788. Calvert was a politician and planter in colonial Maryland. Mount Airy was most likely a gift from his father, Lord Baltimore, who had ensured that Calvert would be provided with lands and revenues, and Mount Airy had originally been a hunting lodge for Charles Calvert, 3rd Baron Baltimore. Calvert began construction of his house, which still survives, in 1751.
In 1774, Calvert's daughter Eleanor Calvert (1758–1811), married John Parke Custis, son of Martha Washington and the stepson of George Washington. Washington himself did not approve of the match owing to the couple's youth, but eventually gave his consent, and was present at the wedding celebrations, which took place at Mount Airy.
 The couple's son, George Washington Parke Custis, who was born at Mount Airy in 1781, built and named Arlington House near the Potomac River, married Mary Lee Fitzhugh, and became the father-in-law of Robert E. Lee. By the 1770s Benedict Swingate Calvert controlled a large and profitable estate of around 4,000 acres (16 km2), with upwards of 150 slaves. He was also an enthusiastic horse breeder, training thoroughbreds and running them in competitions in Maryland and Virginia. Benedict Swingate Calvert died at Mount Airy on January 9, 1788. He was buried beneath the chancel of the church of St Thomas in Croom, Prince George's County, Maryland, a church which Calvert had helped to found and maintain. His wife died ten years later, in 1798.
Benedict Calvert's second son Edward Henry Calvert, who was born on November 7, 1766, then inherited the estate. He married on March 1, 1796, and died on July 12, 1846. He left the estate to his widow, who died on March 26, 1857. On her death the estate, by this time reduced to around 1,000 acres (4.0 km2), was to be divided among her children. Two of her children were the last Calvert owners. After the death of "Old Miss Eleanor" the house and its contents were sold at auction.
Matilda Duvall purchased the property in 1902, ending the Calvert family's hereditary ownership. Renamed as Dower House, it became a country inn until a fire in 1931 reduced the building to only its masonry walls. The ruins were purchased and restored by socialite Cissy Patterson, the publisher of the Washington Times-Herald, who entertained presidents and other important persons here. She in turn bequeathed the property to Ann Bowie Smith, and it was from her family that the State of Maryland purchased Mt. Airy, in 1973, to add it to Rosaryville State Park. It is operated as an event facility by a private concessionaire, Pineapple Alley Catering.
- U.S. Geological Survey Geographic Names Information System: Rosaryville State Park
- "FY2013 DNR Owned Lands Acreage Report". Maryland DNR. Retrieved December 2, 2013.
- "Rosaryville State Park". Maryland DNR. Retrieved December 2, 2013.
- Society of the Ark and the Dove (31 October 2005). George E. & Donna V. Russell, ed. The Ark and the Dove Adventurers. Genealogical Publishing Company. p. 8. ISBN 9780806317625. Retrieved January 28, 2010.
- Callcott, Margaret Law (1 February 1992). Mistress of Riversdale: The Plantation Letters of Rosalie Stier Calvert, 1795-1821. JHU Press. p. 17. ISBN 9780801843990. Retrieved February 1, 2010.
- Yentsch, Anne E. (12 May 1994). A Chesapeake Family and Their Slaves: A Study in Historical Archaeology. Cambridge University Press. p. 262. ISBN 9780521467308. Retrieved January 2010.
- Letters of George Washington Retrieved July 31, 2010
- Maryland: Federal Writer's Project, p.465, A Guide to the Old Line State, Scholarly Pr (1973). Retrieved January 20, 2010
- John Martin Hammond (1914). "Colonial Mansions of Maryland and Delaware: Mount Airy". Prince George's County, Maryland, Genealogy Trails. J.B. Lippincott. Retrieved August 10, 2010.
- Maryland Historical Society. "Mount Airy". The Historical Marker Database. Retrieved June 6, 2011.
- Rosaryville Conservancy. "History: Mounty Airy Mansion". Mount Airy Mansion. Retrieved June 7, 2011.
- Yentsch, Anne E. (12 May 1994). A Chesapeake Family and Their Slaves: A Study in Historical Archaeology. Cambridge University Press. p. 264. ISBN 9780521467308. Retrieved January 2010.
- Rosaryville State Park Maryland Department of Natural Resources
- Mount Airy Mansion Rosaryville Conservancy
- Pineapple Alley Catering, Inc.