He served as Secretary of the Revolutionary War Board in Philadelphia from 1779 to 1781. After, he returned to Maryland and married Rebecca Lowndes, daughter of a Bladensburg, Maryland, founder and niece of Thomas Bladen, Governor of Maryland. In 1783 Stoddert became a partner in the prosperous Georgetown shipping firm of Forrest, Stoddert and Murdock with branches in France and England. He acted as President Washington's confidential agent during the early negotiations for the establishment of the District of Columbia, and his home was the scene of frequent informal conferences important to the shaping of national as well as local history.
Halcyon House's interior was greatly altered in the 20th century, particularly in the period 1900-1938, but the original freestanding brick Georgian mansion remained reasonably intact within the shell of the new house. For some 20 years through the late 1990s, the house was restored to its original appearance.
DC designation: November 8, 1964
National Register listing: March 31, 1971