During the years 1919-1920 an elegant town house was designed and erected by architect William Adams Delano, of the firm Delano and Aldrich for Mr. and Mrs. Harold Irving Pratt. Only the best materials available were used in constructing the house which is reputed to have cost over one million dollars in 1920. It is interesting to trace the story of the house and its owners.

Mr. Harold Irving Pratt was the youngest of Mr. Charles Pratt’s eight children. Mr. Charles Pratt merged Pratt Astral oil with John D. Rockefeller’s Standard Oil of New Jersey, during the latter part of the 19th century. Mr. Harold Irving Pratt was the managing director of Charles Pratt and Co and was also a Council on Foreign Relations member from 1923 until 1939.

Due to the Great Depression, in 1944 the house was boarded up as no one was living in it. With the Council outgrowing its original space, Mr. Hamilton Fish Armstrong telephoned Mrs. Pratt to see if she would donate her house. The next day Mrs. Pratt called to say that she would give the House to the Council. The House officially opened as the Council on Foreign Relations’ new headquarters on April 16, 1945.

The exterior of the house is limestone, custom made in the United States and the inside floors are mainly parquet, oak, or a self-polishing marble. As is typical of other houses of the period, a large kitchen and service area were installed in the basement. The Pratt’s dining room was on the main floor where the current Drawing Room now exists.

Up the winding staircase on the second floor was a library which also functioned as a dining room.

The current Mansion Ballroom was the Pratt’s formal drawing/living room. At Mrs. Pratt’s insistence it was square, being modeled after a room she had seen in Ireland. It is decorated with pine paneling and beautiful chandeliers each of whose crystals are different.
It was also Mrs. Pratt’s wish to use the hand-painted Venetian type doors for the entrance to the library and the drawing room, although the architect demurred that they did not fit with the English architecture.

The Pratt family gave three paintings of themselves seated with the original furnishings. These are located in the marble Franklin Hall and over the mantel of the sitting room. To this day, the Council has maintained its original integrity.