- August 25, 1921. A peace treaty is signed with Germany in Berlin, nearly three years after World War I fighting ends.
- 1922. Gandhi is arrested in India for civil disobedience and is imprisoned for six years.
- January 10, 1923. U.S. occupation troops in Germany are ordered home.
- 1924. The Dawes Plan, a program to reorganize German debt payments and stabilize the German currency, is introduced.
U.S. Politics & Government
- 1921. Warren G. Harding is inaugurated as President.
- October 3, 1922. The first female United States Senator, Mrs. W. H. Felton of Georgia, is appointed by the Governor after the seat is vacated mid-term.
- August 3, 1923. At 2:30 in the morning, while visiting in Vermont, Vice President Calvin Coolidge receives word that he has become President, following the death of Harding.
- November, 4, 1924. Coolidge is reelected.
- The first woman Governor of a U.S. state, Nellie Tayloe Ross of Wyoming, is elected.
Companies, Inventions, Discoveries & Technologies
- October 5, 1921. First radio coverage of the Major League Baseball's World Series.
- August 28, 1922. First radio commercial is broadcast over WEAF in New York City.
- 1922. Philo T. Farnsworth, a 15 year old Idaho schoolboy, designs an image dissector system that is later used to help develop TV.
- 1922. First portable radio and first car radio are manufactured.1922. Herbert Kalmus makes first successful use of the Technicolor process, which began to be widely used to create color films after WWII.
- December 6, 1923. First radio broadcast of a Presidential address.
- 1923. There are 15 million cars registered in the United States. One out of four families either bought or sold a car during the year.
- 1924. Over 2.4 million radios are in American homes.
Humanities & the Arts, Entertainment & Sports
- 1921. Edith Wharton wins the Pulitzer Prize in the Novel category for The Age of Innocence.
- 1921. Knee length skirts become fashionable.
- 1922. The Women's Amateur Athletic Association is founded.
- 1922. T.S. Eliot's classic long poem, The Wasteland, is published.
- 1922. The novel Billy Budd, Foretopman by Herman Melville is published posthumously.
- 1922. Jazz music peaks in popularity.
- 1922. Robert Flaherty, know as the "father of documentary," produces Nanook of the North, an ethnographic film about Eskimos.
- 1923. Maude Howe Elliott and Laura Howe Richards are the first women to win the Pulitzer Prize for biography, sharing the award for their profile of their mother, Julia Ward Howe. In this same year, Edna St.Vincent Millay becomes the first women to win the Pulitzer Prize for poetry.
- 1923. Yankee Stadium is built in The Bronx, New York.
- 1921. The Ku Klux Klan, a white supremacist group, is resurgent in the southern United States.
- May 30, 1922. The Lincoln Memorial is dedicated in Washington, DC.
- July 10-21 1925. The "Scopes Monkey Trial" takes place in Dayton, Tennessee. John T. Scopes is arrested on May 5th for teaching the theory of evolution in violation of state law. He is convicted and fined $100.
- 1925. The name Duke University is adopted by Trinity College in Durham, North Carolina to meet the terms of a $40,000,000 endowment established by James B. Duke.