The Bridge Roebling Built Before He Built the Other One

Wire, Towers and a River to Cross

John A. Roebling had been thinking about this crossing since the 1840s. The Ohio River at Cincinnati ran roughly a thousand feet wide at the proposed site, a distance that defeated every timber and iron-truss technology available to a mid-century engineer. Roebling's answer was a stiffened wire-cable suspension span — the same principle he had already proved at Niagara Falls in 1855, but on a scale that had no precedent over navigable water. In 1856 the Ohio legislature authorised a bridge between Cincinnati and Covington, Kentucky. Roebling was appointed engineer.

The Civil War interrupted everything. Ironically, the military emergency that stalled civilian construction also demonstrated the bridge's strategic value: Union commanders urgently needed a fixed crossing at that bend in the river, and the half-built towers stood through the war as a promise and a problem simultaneously. Construction resumed in earnest in 1863, and by December 1866 the span was open to traffic.

At 1,057 feet between the two towers ↗, it was the longest suspension bridge in the world — a record it held until Roebling's own Brooklyn Bridge surpassed it in 1883. The two limestone-faced towers rise 230 feet above the river, pierced by pointed Gothic arches through which the roadway passes — an aesthetic choice that tied the structure visually to the church architecture then dominating both Cincinnati and Covington's skylines.

What Roebling Proved Here

The engineering substance of the Covington–Cincinnati bridge was not the span length alone; it was the method by which the cables were made. Roebling specified parallel wire cables spun in place, each composed of thousands of individual iron wires drawn to consistent gauge and bound into a single cylindrical rope. At Cincinnati he had enough wire, enough elevation and enough room to perfect the aerial spinning process his firm had first attempted at Niagara. Every decision made on the Ohio — the number of wires per strand, the wrapping technique that sealed the bundle against moisture, the geometry of the suspender rods that transferred deck load back to the cable — was documented, tested under real traffic loads and carried directly into the Brooklyn design.

The deck configuration followed the same logic: a stiffening truss running along both edges of the roadway to prevent the oscillation that had brought down the Tacoma Narrows bridge nearly a century later, and which the Wheeling Suspension Bridge, built by Charles Ellet Jr., had suffered in a windstorm in 1854. At Cincinnati, the stiffening truss was deep enough to make the deck behave almost like a rigid beam. Brooklyn's engineers, including Roebling's son Washington — who took over after his father's fatal injury in 1869 — cited the Cincinnati measurements explicitly when specifying the Brooklyn truss dimensions.

The anchorage system was the third critical transfer. Roebling buried massive masonry anchor blocks on both banks, through which the cables pass at a calculated angle before being spread into individual wire bundles and attached to iron anchor plates. The geometry ensured that tension in the cable translated into compression in the masonry — a material that resists compression far better than it resists tension. Brooklyn's anchorages follow the same principle at larger scale ↗, and Washington Roebling's construction reports from the 1870s reference the Cincinnati performance data directly.

Over-the-Rhine's stock of Italianate and Italianate-Romanesque buildings makes it one of the largest nineteenth-century Italianate districts in the country.

Photo: Vine Street, Over-the-Rhine, Cincinnati, OH · Wikimedia Commons

The Bridge That Stayed

The Covington anchorage gives visitors the clearest sense of the bridge's mass. From the Kentucky side, the towers appear to compress and loom; from the Ohio side they frame the Cincinnati skyline in a way that no photograph quite captures without standing on the deck itself. The bridge — now named the John A. Roebling Suspension Bridge — carries vehicle and pedestrian traffic across the Ohio on a route that has been uninterrupted since 1866, making it one of the oldest continuously operating major suspension bridges in the country.

It was added to the National Register of Historic Places ↗ in 1975. What strikes any engineer looking at it is not just that it works, but that it works in the same way Brooklyn works — the cables, the towers, the anchorages and the stiffened deck forming a system that Roebling assembled here first, on a river in Ohio, seventeen years before he got the chance to repeat it in New York.