It was to have a minimum span length of , but the spans were of 352 and 380 feet (107 and 116 m). It was built high enough to allow steamboats to pass underneath on their way through the Falls of the Ohio along the Portland Canal; in fact, the bridge was built higher than was required, raising the cost of the bridge by $150,000.
The United States Congress approved the building of such a bridge on February 17, 1865, stating that it must not interfere with river traffic. As there were no bridges across the Ohio River at Cincinnati or any place west, including Louisville, crossing the river during the winter months during the war years stressed the need for such a bridge.