The first commercial radio station, KDKA, began broadcasting in Pittsburgh, Pennsylvania.
The first crossword puzzle was published in the New York World newspaper.
The first successful flight across the Atlantic Ocean was made by British aviators Alcock and Brown.
Prohibition went into effect in the United States, making it illegal to manufacture, sell, or transport alcohol.
The Red Scare swept the United States, as the government and public became increasingly fearful of communist and anarchist activity.
The first commercial air service between London and Paris began.
The American Civil Liberties Union (ACLU) was founded, dedicated to protecting individual rights and liberties.
The first world championship of professional golf was held, with American golfer Jock Hutchison winning the title.
The first Grand Prix motor racing championship was held in Le Mans, France.
The popular comic strip "Happy Hooligan" made its debut.
The 19th Amendment to the U.S. Constitution was ratified, granting women the right to vote.
The League of Nations was established as an international organization with the aim of preserving peace and security.
The Treaty of Trianon was signed, officially ending World War I for Hungary.
The Treaty of Moscow was signed, ending the Russo-Polish War and establishing the borders between Russia and Poland.
The Black Sox Scandal occurred in Major League Baseball, in which eight players from the Chicago White Sox were accused of intentionally losing the 1919 World Series.
The Summer Olympics were held in Antwerp, Belgium.
The Polish-Soviet War broke out, which lasted until 1921.
The Kapp Putsch took place in Germany, a failed coup attempt led by Wolfgang Kapp and other right-wing military leaders.