Economic growth continued, propelled by immigration and industrialization, and Brooklyn established itself as the third-most populous American city for much of the 19th century. The waterfront from Gowanus Bay to Greenpoint was developed with piers and factories. Industrial access to the waterfront was improved by the Gowanus Canal and the canalized Newtown Creek. was the most famous product of the large and growing shipbuilding industry of Williamsburg. After the Civil War, trolley lines and other transport brought urban sprawl beyond Prospect Park and into the center of the county.