Andrew Carnegie's first residence was in the St. Nicholas hotel near City Hall park; then he moved to the Windsor Hotel at Fifth Avenue and 46th Street, and after his marriage in 1887 moved again to 5 West 51st Street. In 1898 he purchased land on Fifth Avenue and 90th Street, further north than most mansions, and asked his architects Babb, Cook & Willard for the "most modest, plainest, and most roomy house in New York." It was also the first American residence to have a steel frame and among the first to have a private Otis Elevator and central heating. The Carnegies moved into their new home in 1903.