A bridge across the Narrows had been proposed as early as 1926 or 1927, when structural engineer David B. Steinman brought up the possibility of such a crossing. At the time, Staten Island was isolated from the rest of New York City, and its only direct connection to the other four boroughs was by the Staten Island Ferry to South Ferry in Manhattan, or 39th and 69th Streets in Brooklyn. In 1928, when the chambers of commerce in Brooklyn, Queens, Long Island, and Staten Island announced that the Interboro Bridge Company had proposed the future construction of the "Liberty Bridge" to the United States Department of War. The bridge's towers would be high and it would cost $60million in 1928 dollars. In November 1929, engineers released plans for the Liberty Bridge spanning the Narrows, with 800-foot-tall towers. It was hoped that the new construction would spur development on Staten Island, along with the Outerbridge Crossing and the Bayonne Bridge, which were under construction at the time.