Road Trip Saturday! Today, we have reached the road that was the first United States Highway, reaching across Indiana from Cumberland, Maryland, to Vandalia, Illinois. When the US highway system was finally put in place in 1926, it became US 40. But the description of the route when the Great Renumbering happened is that the US 40 designation would replace the SR 3 name it had acquired in 1917. Today…the National Road. Or a close facsimile thereof!