"...it is Roebling's 1840 patent for the in-situ spinning of wire rope that has to be recognized as one of the decisive breakthroughs in modern suspension bridge technology. This patent brought John Roebling a commission to build a cable-suspended, wooden aqueduct over the Allegheny River in 1845. Roebling built a number of such aqueducts before receiving two major bridge commissions in his mid-career: his 821-foot-span Niagara rail bridge of 1841-55 and his 1,000-foot span Cincinnati Bridge of 1856-67; both of which were prototypes for the 1,600 foot Brooklyn Bridge, whose construction ran through two generations of Roeblings between 1869 and its completion in 1883. The twin masonry support towers of this vast span necessitated the building of foundations 78 feet below the water level...

— Kenneth Frampton and Yukio Futagawa. Modern Architecture 1851-1945. p31.

Details

Length of river span: 1595.5 feet
Total length of bridge: 5989 feet
Width of bridge floor: 85 feet
Suspension cables: four, each 15.75 inches in diameter and 3578.5 feet long, containing 5434 wires each, for a total length of 3515 miles of wire per cable
Foundation depth below high water, Brooklyn: 44 feet 6 inches
Foundation depth below high water, Manhattan: 78 feet 6 inches
Tower height above high water: 276 feet 6 inches
Roadway height above high water: 119 feet (at towers)
Total weight, not including masonry: 14,680 tons

Source: Blue Guide to New York, 1991, p616. ISBN 0393304868.