That highway was one of the early automobile highways of the U.S. It was established in 1912 and eventually extended 3096 miles from Washington, D.C. to Los Angeles, CA. The highway’s name comes from the fact that it incorporated older trails like Braddock’s Road, the National Road, the Boone’s Lick Road, the Santa Fe Trail, and the Grand Canyon Route. In 1926 the NOTH was supplanted by several numbered highways---including US 40, US 50, US 350, US 85, US 60, and US 66---when the Federal Highway System was established. But the Daughters of the American Revolution kept the memory of the NOTH alive by placing Madonna of the Trail statues in all the twelve states the highway crossed. One of those statues stands in Vandalia on the corner of the Old State Capitol.
In Vandalia (according to an old AAA guidebook), the NOTH followed Gallatin St. to Sixth St., then Sixth St. to Edwards St., then Edwards St. to Seventh St., then Seventh St. to South Street (St. Louis Avenue). This route was simplified to: Gallatin Street to Seventh Street to St. Louis Avenue. The NOTH in Illinois was also called Illinois State Route 11 until 1926, when the number/name changed to US 40.