The idea of spanning the Ohio River at Cincinnati had been debated for decades before construction began. When Abraham Lincoln was elected in November 1860 and the Civil War erupted months later, the river became a strategic divide between Union Ohio and the contested border of Kentucky. Confederate forces threatened to besiege Cincinnati. A temporary pontoon bridge was thrown across for troop movements, and it became painfully obvious that the city needed a permanent crossing. Money suddenly materialized. Bonds were sold, and by January 1863 materials began arriving. But the war that created urgency also created obstacles. The workforce was depleted by enlistment. Threats of Confederate invasion halted progress twice. Only one stone tower could be worked on at a time due to labor shortages. The bridge company's president died during the delays. Between 1859 and 1863, no work was done at all. When construction finally resumed in the spring of 1863, the required clearance for the main span had been lowered to speed things along.

The cabling of the bridge was a public spectacle. In September 1865, workers laid the first two wire ropes by unwinding them from a spool mounted on a barge, letting them sink to the riverbed, then raising them in unison. A crude footbridge was strung for the workers. Then began the mesmerizing process of spinning the main cables -- about eighty wires placed per day, watched by hundreds of spectators from both shores. On June 23, 1866, the last of 10,360 individual wires was drawn across the river. These were compressed and wrapped into two cables of 5,180 wires each. Roebling had purchased the wire from Richard Johnson's mill in Manchester, England, preferring its superior tensile strength over domestic alternatives. Anchorages on both shores were built from limestone and freestone, with eleven-ton iron anchors embedded in each block, secured by wrought iron chain links of Roebling's own patented design. Suspenders were hung, and oak lumber was laid as decking across 300 wrought iron beams. Two streetcar tracks ran down the center. Only two men died during the entire construction.

The Roebling Suspension Bridge was more than an Ohio River crossing. It was a laboratory. The diagonal stay cables that Roebling added to stiffen the deck and dampen vibration were an innovation he would carry directly to his design for the Brooklyn Bridge, begun just two years later. The stone towers, built to carry far more weight than the original wooden deck demanded, demonstrated Roebling's philosophy of engineering generous safety margins into his structures. That foresight paid off in 1896, when the bridge received a second set of main cables, a wider steel deck, and a longer northern approach -- a reconstruction that extended its useful life through the 20th century and beyond. The bridge was repainted its distinctive blue color in 1894. Electric lighting arrived in 1901. Originally called the Covington-Cincinnati Suspension Bridge, it was renamed in honor of its designer on June 27, 1983, and designated a National Historic Civil Engineering Landmark the same year.

When the bridge formally opened on January 1, 1867, the toll schedule reflected a world of horses and foot traffic. A horse and buggy paid fifteen cents. Three horses and a carriage cost a quarter. Pedestrians paid one cent. Streetcars ran across its deck for decades until service ended in the 1950s, when the ramps onto the Dixie Terminal were rebuilt for diesel buses. The privately owned Covington-Cincinnati Bridge Company operated the span until Kentucky purchased it in 1953 for $4.2 million. Tolls continued until 1963, when the Brent Spence Bridge opened on Interstate 75 just downstream. Over the following decades the bridge endured periodic closures for repainting, rehabilitation, and the occasional piece of falling sandstone. In 2007, Kentucky reduced the weight limit to eleven tons after a University of Kentucky structural analysis, banning buses entirely. The bridge closed for a nine-month rehabilitation in 2021, but it keeps reopening -- a 160-year-old structure still carrying traffic across the river it was built to span.

When Roebling designed the bridge, the Ohio River was often only a few feet deep. The hundred-foot vertical clearance was dictated not by water but by steamboats, whose tall stacks needed room to pass beneath without showering sparks onto wooden hulls. As railroads replaced river commerce and barges supplanted steamboats, the Army Corps of Engineers dammed the Ohio to control flooding and ensure reliable navigation. By the 1950s, concrete and steel dams had raised the normal pool at Cincinnati to about twenty-six feet, reducing the bridge's clearance to roughly seventy-four feet. The world changed around the bridge -- the river rose, the steamboats vanished, the streetcars gave way to automobiles, and the tolls were abolished -- but the stone towers and wire cables that Roebling strung across the Ohio still hold.