The Hudson River Bridge Company was incorporated April 9, 1856. Work on the bridge was begun in April 1864. The earlier Green Island Bridge had opened to the north in Troy in 1835, but required the longer route of the Schenectady and Troy Railroad west from Troy. The new bridge, called the Hudson River Bridge, was to connect directly to the New York Central Railroad on the west (Albany) side of the bridge and to the Hudson River Railroad, Troy and Greenbush Railroad and Boston and Albany Railroad on the east (Rensselaer) side. The turntable bridge was 4800 feet (1500 m) long, with a clearance of 30 feet (9 m) from high water when closed.