A little history about Williamsburg and the bridge (courtesy of Wikipedia):
In 1638 the Dutch West India Company first purchased the area's land from the local Native Americans. In 1661, the company chartered the Town of Boswijck, including land that would later become Williamsburg. After the English takeover of New Netherland in 1664, the town's name was anglicized to Bushwick. During colonial times, villagers called the area "Bushwick Shore." This name lasted for about 140 years. Bushwick Shore was cut off from the other villages in Bushwick by Bushwick Creek to the north and by Cripplebush, a region of thick, boggy shrub land. Bushwick residents called Bushwick Shore "the Strand."
Farmers and gardeners from the other Bushwick villages sent their goods to Bushwick Shore to be ferried across the East River to New York City for sale via a market at present day Grand Street. Bushwick Shore's favorable location close to New York City led to the creation of several farming developments. Originally a 13-acre (53,000 m2) development within Bushwick Shore, Williamsburg rapidly expanded during the first half of the nineteenth century and eventually seceded from Bushwick and formed its own independent city.
In 1855, the City of Williamsburg, along with the adjoining Town of Bushwick, were annexed into the City of Brooklyn as the so-called Eastern District. During its period as part of Brooklyn's Eastern District, the area achieved remarkable industrial, cultural, and economic growth, and local businesses thrived. Wealthy New Yorkers such as Cornelius Vanderbilt and railroad magnate Jubilee Jim Fisk built shore-side mansions.
In 1898, Brooklyn became one of five boroughs within the City of Greater New York, and the Williamsburg neighborhood was opened to closer connections with the rest of the new city. Just five years later, the opening of theWilliamsburg Bridge in 1903 further opened up the community to thousands of upwardly mobile immigrants and second-generation Americans fleeing the overcrowded slum tenements of Manhattan's Lower East Side. Williamsburg itself soon became the most densely populated neighborhood in New York City, which in turn was the most densely populated city in the United States.
The Williamsburg and Manhattan Bridges are the only suspension bridges in New York City that still carry both automobile and rail traffic