With a long and intriguing history dating back to the late 1700s, this federal style house embodies the history and culture of historic Georgetown and Washington, DC.

The National Society of The Colonial Dames of America, an organization dedicated to the promotion and enhancement of the local culture, currently resides at the property. In October 2016, the property was closed to visitors as Quinn Evans Architects and Gipe Assoc. (MEP Engineering) began work intended to address mechanical systems problems and window restorations.  

Enhancing Visitor Experience

The restoration project included a brand new VRF heating and cooling system, which will now provide a more comfortable environment for visitors and employees alike. The system also allows caretakers to store artifacts in optimally conditioned spaces; a key advantage for the organization. To allow for this new system to perform at maximum efficiency, the exterior envelope was improved by restoring the historic windows and adding interior storm windows. This window work was performed by the well-known window restoration contractor The Craftsman Group, who have done similar work for other QEA projects.  
Restoration work was performed by Corbett Construction, who have also partnered with QEA for the restoration of projects such as The Sulgrave Club, 1220 Connecticut Avenue, and The Octagon House, all in Washington, DC.  

From Past to Present

As research and historic documents show, Samuel Jackson, a merchant from Pennsylvania, built Dumbarton House in 1799 on a tract of land called Rock of Dumbarton. After running into some financial difficulties, Jackson ended up losing the house and property. Later in 1805, Joseph Nourse, the first Register of the Treasury, purchased the house and lived on the property until 1813, when he sold it to Charles Carroll.  
The house changed hands several more times and underwent several modifications over the next 100+ years. The most significant modification occurred in 1915 when the house had to be moved further north as a result of road construction on Q Street. A new foundation was poured for the main block and the house was set on top of it. However, since the wings and hyphens were built without basements, they could not be moved and were torn down. As a result, the wings were rebuilt, attached to the central block by new two-story enclosed hyphens. This configuration and location remains largely unchanged today.  
In 1929, The National Society of The Colonial Dames of America (NSCDA) purchased the property and remains its owner to this day. By 1932 the house underwent several modifications and opened its doors as a house museum depicting life in Georgetown in the 19th century. 
More work was performed on the property in the 1960’s when the site was expanded to the east with the donation of additional land. In 1991, another major renovation project added the Belle Vue room and an elevator to connect 5 levels. This project also included reorganization of the basement and wing spaces.