The bridge for which Bridge Street is named was in fact two bridges, the original for vehicles and pedestrians, supplemented in 1906 by another for trolleys. Each bridge had two spans, first over the mill canal, then over the Pawcatuck. The highway bridge has been replaced, but the trolley's survives. The two segments present a nice comparison in nineteenth-century metal bridge technology. The short span over the millrace are Pratt pony trusses of a type built since 1844 and still in use today. The long span over the River are Baltimore trusses of a type used between 1831 and the beginning of the twentieth century.