Route 66, the iconic American highway stretching roughly 2,400 miles from Chicago to Santa Monica, California, marks its 100th anniversary this year. The highway was designated as one of the nation's original numbered routes in November 1926, connecting the industrial Midwest to the Pacific coast through Missouri, Kansas, Oklahoma, Texas, New Mexico and Arizona.

Oklahoma businessman Cyrus Avery, known as the Father of Route 66, envisioned the highway as more than just efficient transportation. The route was assembled from existing Native American trading routes and dirt roads, with the goal of linking rural America and creating new commercial opportunities. Avery deliberately chose the number 66 for its marketing potential, a decision that proved prescient as the highway became immortalized in American culture through literature, music and film.

During its heyday from the 1940s through 1950s, Route 66 served multiple critical functions in American history. It became a literal path of hope for migrants fleeing the Dust Bowl and Great Depression in the 1930s, earning the nickname "Mother Road" from author John Steinbeck. During World War II, the highway facilitated the movement of troops, equipment and workers westward. The postwar economic boom transformed it into a popular vacation route as cars became more affordable and Americans gained disposable income.

The highway's cultural impact extended beyond transportation, spawning a distinctive roadside economy of diners, motels and attractions. Entrepreneurs created elaborate tourist draws including rattlesnake pits, trading posts, and engineering marvels like St. Louis' Gateway Arch. The route also played complex roles for different communities: it provided economic opportunities for Native American tribes whose land it crossed, though sometimes through eminent domain, and offered safe havens for Black travelers during segregation, though many faced restrictions in "sundown towns."

Route 66 was decommissioned as a federal highway in 1985 following the development of the interstate highway system under President Dwight Eisenhower. However, preservation efforts led by figures like Arizona barber Angel Delgadillo have maintained much of the route's historical significance. Today, more than 250 of the highway's buildings, districts and road segments are listed on the National Register of Historic Places, and over 90% of the road remains drivable in California. The highway continues to attract international visitors seeking what many consider the quintessential American road trip experience.