Henry Janeway Hardenbergh FAIA was an American architect, best known for his hotels and apartment buildings, and as a "master of a new building form — the skyscraper." He worked three times with Edward Clark, the wealthy owner of the Singer Sewing Machine Company and real estate developer: The Singer company's first tower in New York City, The Dakota Apartments, and its precursor, the Van Corlear. He is best known for building apartment dwellings and luxury hotels.

Detlef Lienau was a German architect born in Holstein. He is credited with having introduced the French style to American building construction, notably the mansard roof and all its decorative flourishes. Trained at the École des Beaux-Arts, Paris, he designed virtually every type of Victorian structure—cottages, mansions, townhouses, apartment houses, hotels, tenements, banks, stores, churches, schools, libraries, offices, factories, railroad stations, and a museum. Lienau was recognized by clients and colleagues alike as one of the most creative and technically proficient architects of the period, and was one of the 29 founding members of the American Institute of Architects.