The David McCullough Bridge, commonly and historically known as the 16th Street Bridge, is a through arch bridge that spans the Allegheny River in Pittsburgh, Pennsylvania.The 16th Street Bridge replaced the Mechanics Street Bridge which had been completed at the behest of the State of Pennsylvania in 1838. The 16th Street Bridge was constructed in 1922 with a length of 1,900 feet (580 m) and a width of 40 feet (12 m). The bridge was listed on the National Register of Historic Places in 1979.