Constructed from 1936 to 1938, when it opened in 1938 theArrigoni Bridge was the most expensive bridge, costing $3.5 million. With two 600 feet (180 m) steel arches, the bridge is still the longest in the state. In 1938 it won the American Institute of Steel Construction’s first prize “Most Beautiful Steel Bridge” in the large bridge category.The bridge is somewhat of an icon and landmark in the area and is also a marker of where the water begins to freeze in the river (as south of this point the tides are able to bring enough salt water north to keep the water from freezing over.) It was named after the state legislator who promoted the project, Charles J.Arrigoni, and was designed by William G. Grove of the American Bridge Company and Leslie G. Sumner of the State Highway Department.

Source: Wikipedia