The property was originally called "Peterstone" in 1691. It descended to several farmers until 1791 when John Ross bought it. Samuel Breck, the husband of Ross' daughter, later came into possession and built "Sweetbriar" Mansion in 1797 to escape the Yellow Fever epidemic, which killed 10,000 Philadelphians between 1793 and 1800.
Due to his schooling in France, Breck soon made "Sweetbriar" a gathering place of the French diplomatic corps, which included his friend Marquis de Lafayette. Breck also became a state senator and congressman; founded the Savings Fund Society; and was Trustee of the University of Pennsylvania. Other notables important to the Breck family at this time were Joseph Bonaparte and Dr. Benjamin Rush.
Bitter irony touched the Brecks in 1828 when their only child, Lucy, died during an epidemic of River Fever (Typhus). Broken-hearted, they closed "Sweetbriar" and sold the house ten years later.
"Sweetbriar" is built of local rubble-stone covered with stucco, a popular building practice in the 18th century. The style, although Federal, shows the continuing influence of Georgian Symmetry. There are many French influences. This may be due in part to Breck's years spent in France. Ornamentation is subtler than on earlier houses like "Mount Pleasant," where bricks outline the belt course and corners of the house. The first floor was designed for entertaining. The floor-to-ceiling windows in the two parlors face the Schuylkill River where, in Breck's day, islands dotted the river. Farm animals grazed on the banks; and woods, gardens and green houses sloped down the river. The "Sweetbriar" estate at this time included 20 acres in all.
The Chinese armorial porcelain, the Hepplewhite and Sheraton style chairs and the Adam style furniture date from the days when Breck entertained General Lafayette at "Sweetbriar." The designs of that period were influenced by archaeological discoveries in the ancient roman houses of Pompeii, as evidenced by the delicate plaster decorations on the fireplaces, and the wedge wood jasperware. The oval looking-glasses, bird prints by John James Audubon and scenes of early 19th century Philadelphia by William Birch are also on display.
In 1869 "Sweetbriar" became part Fairmount Park. It bordered the Centennial Exposition grounds of 1876. In 1877 it was a restaurant and later a day camp for children. The house was restored in 1932 by the Junior League and in 1976 by the City of Philadelphia. Since 1939 "Sweetbriar" has been maintained by the Modern Club, a philanthropic organization, which works in cooperation with the Fairmount Park Commission.