The Italian Renaissance-style mansion known as Harkness House, on 75th Street and Fifth Avenue, manages to project splendor without ostentation.
The home was completed in 1908 as a wedding gift for the son of Stephen Harkness, an Ohio businessman who had invested in Rockefeller’s oil business, according to Untapped Cities.
The lot was purchased in 1906 for $450,000, and the house was built for $550,000. But unlike other mansions of the era, Harkness House attempted a sort of modesty. It lacked a ballroom and all of the rooms were designed to be smaller and feel more intimate.
The house was given over to their family foundation after the last Harkness heir died. The Commonwealth Fund, established in 1918, has occupied the house since 1952 as its headquarters. [Untapped Cities] – Christopher Cameron