This thesis makes an attempt to demonstrate the importance of Route 66 as a main connection between east and west during the decades; how it was used and gradually led to the formation and shaping of the cities, how it contributed to the urbanization. The first two chapters of this thesis introduce how the motorcar industry generated traveling and the need for roads; and they also deal with the establishment of Route 66, - the first east-west paved commercial road of the United States -, the construction of which was essential for such a mobile nation as the American. Further on the essay demonstrates - including a personal experience - the urban growth of those cities and some businesses which stayed connected to the infrastructure; and the decline of those, which were cut off from the new interstate system and remained as old Route 66. Later in the essay an emphasis is put on the military importance of Route 66 and its vital significance for migrating people. There is an attempt to put light on why Route 66 became a legend and appeared in the works of so many artists.