On May 15, 1820, Congress authorized an extension of the road to St. Louis, on the Mississippi River, and on March 3, 1825, across the Mississippi and to Jefferson City, Missouri.
Work on the extension between Wheeling and Zanesville, Ohio, used the pre-existing Zane's Trace of old Ebenezer Zane, and was completed in 1833 to the new state capital of Columbus, Ohio, and in 1838 to the college town of Springfield, Ohio.

In 1849, a bridge was completed to carry the National Road across the Ohio River at Wheeling.
The Wheeling Suspension Bridge, designed by Charles Ellet Jr., was at the time the world's longest bridge span at 1,010 feet (310 m) from tower to tower.
On May 15, 1820, Congress authorized an extension of the road to St. Louis, on the Mississippi River, and on March 3, 1825, across the Mississippi and to Jefferson City, Missouri. Work on the extension between Wheeling and Zanesville, Ohio, used the pre-existing Zane's Trace of old Ebenezer Zane, and was completed in 1833 to the new state capital of Columbus, Ohio, and in 1838 to the college town of Springfield, Ohio.
In 1849, a bridge was completed to carry the National Road across the Ohio River at Wheeling. The Wheeling Suspension Bridge, designed by Charles Ellet Jr., was at the time the world's longest bridge span at 1,010 feet (310 m) from tower to tower.
National Road