Cowan argued in favor of a change to legislation that authorized the construction of a new railroad bridge over the Ohio River at Steubenville, Ohio. Concerned that the bridge would limit the ability of boats and ships to transport cargo on the river, and opposed to what he saw as the expanding power of the Pennsylvania Railroad, Cowan supported revising the initial proposal, which resulted in lengthening the span to 300 feet and raising the deck to 90 feet above water level, which ensured that steamboat smokestacks would be able to clear it.