From top to bottom, left to right: The
Prohibition era officially begins as the
Eighteenth Amendment and the
Volstead Act come into effect, banning the manufacture, sale, and transportation of alcoholic beverages across the
United States, triggering a decade of speakeasies, bootlegging, and organized crime; the
League of Nations is formally established with its headquarters in
Geneva,
Switzerland, as part of the post-World War I peace framework, aiming to maintain global peace and prevent future conflicts; the
1920 Summer Olympics are held in
Antwerp,
Belgium, symbolizing a return to international unity after World War I and introducing the Olympic flag and athlete's oath; the
Battle of Warsaw becomes the decisive turning point of the
Polish–Soviet War, as Polish forces repel the
Red Army and preserve the independence of the
Second Polish Republic; The
Red Army invasion of Armenia and
Red Army invasion of Azerbaijan lead to Soviet occupation and the incorporation of both Armenia and Azerbaijan into the
Soviet Union, reshaping and consolidating Soviet control over the South Caucasus region; and the
Wall Street bombing devastates
New York City when a horse-drawn wagon explodes in the financial district, killing 38 and injuring hundreds in one of the deadliest terror attacks in U.S. history.