Clarence Dillon (born in San Antonio in 1882) was a self-made financier whose interests in banking and real estate made him one of the country's richest and most influential businessmen during the pre-Depression boom. First associated with mid-western mining and gas interests, he founded the investment banking firm of Dillon, Read & Co. in 1921, around the time that Schmidt became the family architect. Dark Harbor was "discovered" by Philadelphians in July of 1890, and first achieved social prominence in the early 1900s. According to local history, Clarence Dillon purchased the prime land on the southwest shore of Long Island, down harbor from the yacht club and Isleboro Inn, and tore down all or most of an existing house to make his own summer place on a spectacular bluff with a view of the mainland. Plans of the new house in the Avery collection at Columbia University indicate that the masonry wing at the south may have been part of an existing structure. Schmidt's design made the most of the site. By masterfully assembling a series of cottage-like elements in an offset, interlocking block along the shore, he broke down the apparent length of the 200-foot-long house, thus creating a picturesque massing. Built in the shingle and clapboard vernacular of the Maine coast, it can be compared with the second Isleboro Inn, by Edmund C. Evans of 1917, and the Devereux house of the same date by Mellor, Meigs and Howe. It is still owned by the Dillon family.