Directly opposite Hammond-Harwood, this 1769 three-storey brick mansion was begun by Samuel Chase — another signer of the Declaration of Independence — and completed by Edward Lloyd IV after Chase ran out of money. The architect William Buckland took over the interiors before moving across the street to start on Hammond-Harwood, and the two houses are best visited as a pair to see his evolving work.
The cantilevered double staircase, lit by a Palladian window on the landing, is the showpiece interior. Francis Scott Key married Mary Lloyd here in 1802. The house remains in use as a private residence for elderly women (per the 1886 bequest of Hester Ann Chase Ridout, the last family owner) and only the first floor is open for tours on a limited schedule.