The Nineteenth Amendment is ratified, prohibiting denial of the right to vote on the basis of sex in the United States.
The peace treaty ending the war between Germany and the Allies is signed in the Hall of Mirrors, imposing war guilt, territorial losses and heavy reparations on Germany.
In Toronto, insulin isolated by Frederick Banting's team is first injected into a diabetic patient, turning a fatal disease into a manageable one.
The US Congress declares war on the German Empire, bringing the United States into World War I on the Allied side.
The US-built Panama Canal officially opens, linking the Atlantic and Pacific Oceans.
Charles Lindbergh flies solo and nonstop from New York to Paris in the Spirit of St. Louis.
The Jazz Singer, the first feature-length film with synchronised dialogue, premieres in New York, launching the era of talking pictures.