The early 20th century was an era of business expansion and progressive reform in the United States. The progressives, as they called themselves, worked to make American society a better and safer place in which to live. They tried to make big business more responsible through regulations of various kinds. They worked to clean up corrupt city governments, to improve working conditions in factories, and to better living conditions for those who lived in slum areas, a large number of whom were recent immigrants from Southern and Eastern Europe. Many progressives were also concerned with the environment and conservation of resources.
This generation of Americans also hoped to make the world a more democratic place. At home, this meant expanding the right to vote to women and a number of election reforms such as the recall, referendum, and direct election of Senators. Abroad, it meant trying to make the world safe for democracy. In 1917, the United States joined Great Britain and France--two democratic nations--in their war against autocratic Germany and Austria-Hungary. Soon after the Great War, the majority of Americans turned away from concern about foreign affairs, adopting an attitude of live and let live.
The 1920s, also known as the "roaring twenties" and as "the new era," were similar to the Progressive Era in that America continued its economic growth and prosperity. The incomes of working people increased along with those of middle class and wealthier Americans. The major growth industry was automobile manufacturing. Americans fell in love with the automobile, which radically changed their way of life. On the other hand, the 1920s saw the decline of many reform activities that had been so widespread after 1900.