How Does Lewis explain the dull monotony or "universal similarity" reigning in American Life? How many cultures does America have? What is the source of American culture?

Sinclair Lewis defines universal similarity in Main Street through Carol's observation as "the physical expression of the philosophy of dull safety. Nine-tenths of the American towns are so alike that it is the completest boredom to wander from one to another." (p. 239) This reveals itself in the lack of originality in the construction of streets, buildings, in the "neglect of natural advantages." Carol observes, "If Kennicott were snatched from Gopher Prairie and instantly conveyed to a town leagues away, he would not realize it." (p. 240) In Carol's view "Life is comfortable and clea…