Some historians contend that the Progressive movement continued into the 1920s, but that decade is usually seen as one of contradictions and paradoxes. Many Americans enjoyed prosperity while others remained in poverty. Carefree living and outright corruption existed alongside the resurgent puritanism that waged war against liquor and liberalism. Naive idealism about business, technology, and science was accompanied by cynicism and disillusionment with splurges of materialism. Behind the jazz, daring fashions, new experiences of leisure, and hero worship-for example, of football star Red Grange and aviator Charles Lindbergh-lurked fear of the future. Jim Crow laws and threats of lynching denied African Americans the freedoms others enjoyed. Disillusioned over their prospects in America, some followed the call for racial separation issued by Marcus Garvey's Universal Negro Improvement Association in the 1920s. More significant was the Harlem Renaissance, a celebration of African American life by Langston Hughes, James Weldon Johnson, and other writers and artists. At the same time, white literary figures such as Gertrude Stein, Ernest Hemingway, and F. Scott Fitzgerald escaped from American provincialism by moving to the freer atmosphere of Paris.

The still powerful influence of tradional Protestantism was evident in enforcement of prohibition, made possible by the 18th Amendment (1919; repealed by the 21st Amendment, 1933) and in legislation enacted (1924) to limit immigration from eastern and central Europe. It could also be seen in the 1925 Scopes Trial, which tested (and approved) a Tennessee law against the teaching of evolution in schools; opposition to the 1928 presidential candidacy of New York governor Alfred E. Smith, a Roman Catholic; and the activities of the Ku Klux Klan aimed at Catholics, Jews, and blacks. By the 1920s, industry had completed its takeover of the economy, and the myth of America as a prosperous agrarian society was now more mythical than ever; farmers struggled throughout the decade. Labor unions, already weak, lost ground. Membership declined from 5.1 million in 1920 to 4.3 million in 1929.

Automobiles reveal the impact of technology: by 1929 there were 27 million passenger cars on American streets and roads-triple the number of a decade earlier. The love affair with the automobile stimulated buying on the installment plan, trade-ins, planned obsolescence, and highway-construction programs, and it moved courtship from front porches to the back seats of cars. Along with automobiles, movies with sound, radios, vacuum cleaners, washing machines, and other conveniences became signs of the times.