By the end of the 1850s, John Jacob Astor III had erected his mansion on the northwest one corner of 33rd Street and Fifth Avenue and William B Astor II had built his on the southwest corner of 34th Street and Fifth. The latter's address was 350 Fifth Avenue - the address of the Empire State Building. These mansions became the hub of the New York society world, with lavish parties and high-stakes poker games.
