A short distance west of the Springfield city limits at the top of Sugar Grove Hill, the continuous metaled or paved portion of the National Road ended. Outside of the navigable rivers and harbors, it was the first great internal improvement of the fledgling nation, the United States of America. The road began at Cumberland, Maryland, and continued through the mountains to Brownsville; Washington, Pennsylvania; Wheeling, West Virginia; Zanesville, Ohio; Columbus, Ohio; and Springfield, Ohio. The final federal appropriation was made in 1836, and the final federal work on the continuous and contiguous part of the highway was completed west of Springfield in 1838. The road opened a relatively easy route for settlement of the Great Lakes heartland of the United States and in return provided an outlet for the growing number of farm and manufactured products of the area.
