BARBARA KLEIN: In his book, Steinbeck wrote: "66 -- the long concrete path across the country, waving gently up and down on the map ... over the red lands and the gray lands, twisting up into the mountains, crossing the Divide and down into the bright and terrible desert, and across the desert to the mountains again, and into the rich California valleys.”

Steinbeck wrote: "66 is the path of a people in flight, refugees from dust and shrinking land … 66 is the mother road, the road of flight."

STEVE EMBER: In nineteen forty-six, the songwriter Bobby Troup and his wife drove across the country to Los Angeles. He wrote a song about traveling on Route 66. The song told people they could have fun, could get their kicks, on that drive.

In Los Angeles, Bobby Troup took the song to Nat King Cole, who recorded it. It became a huge hit.

(MUSIC: "Route 66"/Nat King Cole)

BARBARA KLEIN: In the nineteen fifties, holiday travel brought more and more families out West to explore. Route 66 represented the spirit of movement and excitement.

In the nineteen sixties, Americans watched a popular television series called "Route 66." It was the story of two young men driving across the country. The show was filmed in cities and towns across America. Yet only a few shows were filmed on the real Route 66.

STEVE EMBER: In real life, people were getting fewer and fewer kicks on Route 66. By nineteen sixty-two, parts of the road were closed because they were in poor condition.