Constructing the National Road through Indiana in the early 19th century was a monumental task that connected people, wealth, and commerce and linked the state to the rest of the nation. Increased westward migration and the enlargement of the United States after the Louisiana Territory purchase in 1803 led the national government to establish a reliable western route, and in 1806 Congress approved the National Road, also known as the Cumberland Road and National Pike. Surveyors and engineers then faced the rocky terrain and steep slopes of the Appalachian Mountains, and it took 20 years of arduous labor to survey and build the route. As the road pushed into western Ohio, Jonathan Knight was sent from Washington, DC, to survey Indiana's segment, beginning in 1827 from the Ohio-Indiana state line and working east and west from Indianapolis across 150 miles. Construction required clearing dense forest along 90 percent of the route, with workers felling trees, removing roots, tearing out stumps, leveling the earth, and dragging the clearing into a rough road. Much of Indiana's section remained rutted, muddy, and unpredictable, with only limited stretches improved by macadam, plank, or corduroy surfacing, and in 1839 J. Gould observed that only short sections at Richmond, Centerville, Indianapolis, and Terre Haute, along with a few bridges, were completed in the same substantial manner as in Ohio. Although shifts in state and federal funding toward rail and canal development prevented completion of a fully paved macadam road across Indiana, many regarded it as the best road yet built in North America. The automobile revived the road in the 1920s, and in 1926 it became U.S. Route 40, a transcontinental highway from Atlantic City, NJ, to San Francisco, CA, bringing new prosperity through gas stations, diners, and motels. Until Interstate 70 was completed in the 1970s, U.S. 40 remained one of the country's primary east-west routes. In 2002 the U.S. Secretary of Transportation designated the Historic National Road from Maryland to Illinois an All-American Road, and Indiana continues working to preserve its part of this historic corridor.