The majority of Americans did not mourn the defeated treaty, for they had grown disillusioned with the results of the war. After 1920, the United States turned inward and withdrew from European affairs.
At the same time, Americans were growing increasingly suspicious of and hostile toward foreigners in their midst. In 1919, a series of terrorist bombings produced what became known as the "Red Scare." Under the authority of Attorney General A. Mitchell Palmer, raids of political meetings were conducted, arrests were made and several hundred foreign-born political radicals - anarchists, socialists and communists - were deported, although most of them were innocent of any crime. In 1921, two Italian anarchists, Nicola Sacco and Bartolomeo Vanzetti, were convicted of murder on the basis of very dubious evidence. Intellectuals protested that Sacco and Vanzetti had been condemned for their political beliefs, but the two men were denied a retrial and, after exhausting all legal procedures, were electrocuted in 1927.
In 1921, Congress had enacted immigration limits, which were tightened in 1924 and again in 1929. These restrictions favored immigrants from Britain, Ireland, Scandinavia and Germany - "Anglo-Saxon" and "Nordic" stock. Small quotas were reserved for eastern and southern Europeans; none at all for Asians.
But the 1920s were anything but normal. It was an extraordinary and contradictory decade, when hedonism and bohemianism coexisted with a puritanical conservatism. It was the age of Prohibition. In 1920, alcoholic beverages were outlawed by a Constitutional Amendment. But drinkers cheerfully evaded the law in thousands of "speakeasies" (illegal bars), and gangsters made fortunes supplying illegal liquor. The Ku Klux Klan, revived in 1915, attracted millions of followers and terrorized blacks, Catholics, Jews and immigrants. At the same time, there was a flowering of black literature - the "Harlem Renaissance" - and jazz caught the imagination of many white Americans, including composer George Gershwin. Also, in 1928 Democrat Alfred E. Smith became the first Roman Catholic to run for president. In 1927, Charles Lindbergh excited the nation when he completed the first nonstop airflight from New York to Paris. In an age of materialism and disenchantment, this modest young aviator reaffirmed for Americans the importance of individual heroism.
For business, the 1920s were golden years of prosperity. The United States was now a consumer society, with a booming market for radios, home appliances, synthetic textiles and plastics. The businessman became a popular hero; the creation of wealth a noble calling. One of the most admired men of the decade was Henry Ford, who had introduced the assembly line into automobile production. Ford was able to pay high wages and still earn enormous profits by manufacturing the Model T - a simple, basic car that millions of buyers could afford. For a moment, it seemed that America had solved the eternal problem of producing and distributing wealth.
There were, however, fatal flaws in the prosperity of the 1920s. With profits soaring and interest rates low, plenty of money was available for investment, but much of that capital went into reckless speculation. Thousands of millions of dollars poured into the stock market, and frantic bidding boosted the prices of shares far above their real value. Many investors bought stocks "on margin," borrowing money from their brokers to cover up to 90 percent of the purchase price. As long as the market prospered, speculators could make fortunes overnight, but they could be ruined just as quickly if stock prices fell. The bubble of this fragile prosperity finally burst in 1929 in a worldwide depression, and by 1932 Americans were confronting the worst economic crisis of modern times. That collapse, in turn, led to the most profound revolution in the history of American social thought and economic policy.