The Ohio River between Clark County, Indiana and Louisville, Kentucky, is lined with historic bridges, including the George Rogers Clark Memorial Bridge, the John F. Kennedy Memorial Bridge, and the Big Four Bridge. The George Rogers Clark Memorial Bridge, completed in Art-Deco style in 1929 as the Louisville Municipal Bridge, was designed by Paul Philippe Cret, built by the American Bridge Company of Pittsburgh, and became the first vehicular bridge across the Ohio at Louisville; it operated as a toll bridge until 1946 and was renamed in 1949 for George Rogers Clark, founder of Louisville and Clarksville, and is listed on the National Register of Historic Places. Farther east, the John F. Kennedy Memorial Bridge was completed in 1963 at a cost of $10 million, carries Interstate 65 traffic, and was named by Kentucky and Indiana officials four days after President Kennedy's assassination. The Big Four Bridge, built for the Cleveland, Cincinnati, Chicago and St. Louis Railroad Company, took nearly seven years to construct, suffered two deadly construction accidents, and was completed in 1895 at a cost of $2.5 million; after becoming outdated in the 1920s, a new span was built using the old bridge as a scaffold, then the original was dismantled. Railroad mergers in 1968 left the newer bridge unneeded, and with its approaches removed it became known as "the bridge that goes nowhere," while plans were underway to make it part of a bi-state greenway. To the west, the Pennsylvania Railroad Bridge was once the longest iron bridge in the United States.