The Main Street of America was built on a 200-year-old ghost road

Countries & Cities · Published 15 October 2026 Swipe more like this →

In short: Long before the Interstate system dominated the landscape, U.S. Route 40 served as a primary artery across the continent. But its true history is layered; it sits atop the National Road, the first federally funded highway project in American history, weaving together centuries of migration and war.

Established in 1926, U.S. Route 40 was designed as a major east–west corridor connecting the Mountain states to the Mid-Atlantic. While it is often called the 'Main Street of America'—a nickname it shares with Route 66—its physical footprint is a palimpsest of American transit. Much of its current path was built directly over the National Road, an act of Congress in 1806 created to connect Cumberland, Maryland, with Vandalia, Illinois. This original federal project served as the foundation for the modern highway, which also incorporates segments of the Victory Highway (a WWI memorial), Zane's Trace, and even parts of the Oregon Trail.

The route's evolution reflects the shift from local commerce to high-speed transit. In many areas, particularly in Illinois, US 40 remains an undivided surface route, having lost most of its non-local traffic to Interstate 70. In other regions, the highway has been functionally replaced or truncated. For instance, west of Silver Summit, Utah, the route was largely superseded by I-80. In Missouri, the highway was originally designated as Route 2 until 1926, and it has undergone significant rerouting, such as the 2008 shift south along K-7 west of Kansas City.

Today, the highway traverses 12 states, passing through major hubs like Denver, St. Louis, and Baltimore. It remains a complex web of concurrencies, running alongside I-70, I-64, and I-95. By preserving these older alignments, US 40 serves as a living museum of American engineering, maintaining the path of the first federally funded roads while navigating the modern demands of 21st-century travel.

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