Brooklyn Bridge

John A. Roebling (1806-1869), a German-born American engineer, designed the Brooklyn Bridge. Roebling was not only a visionary suspension-bridge designer, but was the first to use steel cables in his projects (steel is much stronger than iron, which was commonly used in bridges at the time). Roebling actually invented a machine to twist steel wire into cables; he then opened a factory in Pennsylvania to mass-produce steel cable.

Before the Brooklyn Bridge, Roebling constructed suspension bridges over the Monongahela River at Pittsburgh in 1846; at Niagara Falls in 1854; over the Allegheny River at Pittsburgh in 1860; and over the Ohio River at Cincinnati in 1867. Roebling's suspension bridges were truly modern structures.