The Athenian Empire, established in the 5th century BCE, is often credited with the development of democracy as a system of government.

The Stamp Act, passed by the British Parliament in 1765, imposed a tax on printed materials in the American colonies, sparking widespread protests and leading to the American Revolution.

The assassination of Archduke Franz Ferdinand, heir to the Austro-Hungarian throne, on June 28, 1914, triggered a series of events that led to the outbreak of World War I.

The Battle of Stalingrad, fought between the Soviet Union and Nazi Germany from 1942 to 1943, is considered a turning point in World War II, marking the beginning of the end for Nazi Germany.

The Solidarity movement in Poland, led by Lech Walesa, played a crucial role in the collapse of communism in Eastern Europe and the fall of the Berlin Wall in 1989.

The stock market crash of 1929, also known as Black Tuesday, is widely considered the primary trigger of the Great Depression, leading to a global economic crisis.

The Berlin Blockade, imposed by the Soviet Union in 1948, is often seen as the starting point of the Cold War, a period of tension and rivalry between the United States and the Soviet Union.

The financial crisis of the French monarchy, coupled with the growing discontent among the population, was a major factor leading to the French Revolution in 1789.

The Fall of Saigon in 1975, when North Vietnamese forces captured the South Vietnamese capital, marked the end of the Vietnam War.

The issue of slavery was the primary cause of the American Civil War, as the Southern states sought to maintain their economic and social system based on slavery, while the Northern states opposed its expansion.

The Treaty of Versailles, signed at the end of World War I, imposed harsh conditions on Germany, contributing to widespread resentment and economic hardship, which helped fuel the rise of Adolf Hitler and the Nazi Party.

The economic and social inequality in Russia, coupled with the autocratic rule of Tsar Nicholas II, led to widespread discontent and eventually the Russian Revolution in 1917.

The launch of Sputnik 1, the first artificial satellite, by the Soviet Union in 1957, marked the beginning of the Space Race between the United States and the Soviet Union.

The Cuban Missile Crisis in 1962 was triggered by the Soviet Union's deployment of nuclear missiles in Cuba, just 90 miles from the coast of the United States.

The dissolution of the Soviet Union in 1991 marked the end of the Cold War, as the Soviet Union's collapse led to the end of the bipolar world order.