The 1920s is sometimes referred to as the "Jazz Age" or the "Roaring Twenties", when speaking about the United States and Canada. In Europe the decade is sometimes referred to as the "Golden Twenties". Since the closing of the 20th century, the economic strength during the 1920s has drawn close associations with the 1950s and 1990s, especially in the United States. These three decades are regarded as periods of economic prosperity, which lasted throughout almost the entire decades following a tremendous event that occurred in the previous decade (World War I and Spanish flu in the 1910s, World War II in the 1940s, and the end of the Cold War in the late 1980s).
However, not all countries enjoyed this prosperity. The Weimar Republic, like many other European countries, had to face a severe economic downturn in the opening years of the decade, because of the enormous debt caused by the war as well as the Treaty of Versailles. Such a crisis would culminate with a devaluation of the Mark in 1923, eventually leading to severe economic problems and, in the long term, favour the rise of the Nazi Party.
Additionally, the decade was characterized by the rise of radical political movements, especially in regions that were once part of empires. Communism began attracting large numbers of followers following the success of the October Revolution and the Bolsheviks' determination to win the subsequent Russian Civil War. The Bolsheviks would eventually adopt a policy of mixed economics, from 1921 to 1928, and also give birth to the USSR, at the end of 1922.
The twenties marked the first time in America that the population in the cities surpassed the population of rural areas. This was due to rapid urbanization starting in the 1920s.
The 1920s also experienced the rise of the far-right and fascism in Europe and elsewhere, being perceived as a solution to prevent the spread of Communism. The knotty economic problems also favoured the rise of dictatorships in Eastern Europe and the Balkans, such as Józef Piłsudski in Poland and Peter and Alexander Karađorđević of Yugoslavia.
The Stock Market collapsed during October 1929 (see Black Tuesday) and drew a line under the prosperous 1920s.
Record companies (such as Victor, Brunswick and Columbia) introduce an Electrical Recording process on their phonograph records in 1925 (that had been developed by Western Electric), resulting in a more life-like sound.
Robert Goddard makes the first flight of a liquid-fueled rocket in 1926.
Rise of radical political movements amid the economic and political turmoil after World War I and after the stock market crash such as communism and fascism.
Prohibition of alcohol occurs in the United States in the 1920s. Organized crime related to the illegal sale of alcohol booms in the period such as by Chicago mafia leader Al Capone.
Major armed conflict in Ireland including Irish War of Independence (1919-1921) resulting in Ireland becoming an independent country in 1922 followed by the Irish Civil War (1922-23)
Benito Mussolini of the National Fascist Party became Italy's Prime Minister shortly thereafter creating the world's first fascist government. The Fascist regime establishes a totalitarian state led by Mussolini as a dictator. The Fascist regime restores good relations between the Roman Catholic Church and Italy with the Lateran Pact which creates Vatican City. The Fascist regime pursues an expansionist agenda in Europe such as by raiding the Greek island of Corfu in 1923, pressuring Albania to submit to becoming a de facto Italian protectorate in the mid-1920s, and threatening Yugoslavia with war until the Yugoslav government agreed to allow Italians to freely immigrate into Dalmatia (a region of Yugoslavia claimed by Italian nationalists) with the Treaty of Nettuno.
Germany suffers from economic crisis in the early 1920s and hyperinflation of currency in 1923. French military forces briefly occupy the industrial Ruhr region in Germany from 1923 to 1924 after Germany failed to be able to pay its reparations payments. The recently-formed fringe National Socialist German Workers' Party (a.k.a. Nazi Party) led by Adolf Hitler attempts a coup against the Bavarian and German governments in the Beer Hall Putsch which fails, resulting in Hitler being briefly imprisoned for one year in prison where he writes Mein Kampf.
Women's suffrage movement continues to make gains as women obtain full voting rights in Denmark in 1915, in the USA in 1920, and in the UK in 1918 (women over 30) and in 1928 (full enfranchisement); and women begin to enter the workplace in larger numbers
The Scopes Monkey Trial (1925) which declared that John T. Scopes had violated the law by teaching evolution in schools, creating tension between the competing theories of creationism and evolution.