The stock market crash of October 1929, often referred to as 'Black Tuesday,' marked the beginning of the Great Depression, one of the most severe economic downturns in modern history. Triggered by a series of speculative investments and banking failures, the crash led to widespread unemployment, business closures, and poverty across the United States and beyond.

As the world emerged from the devastation of World War II, there was a strong desire to prevent future conflicts and promote peace among nations. This led to the establishment of the United Nations (UN) in 1945, an international organization created to foster cooperation on global issues, including peace, security, human rights, and development. With 51 founding members, the UN aimed to address the shortcomings of its predecessor, the League of Nations, which had failed to prevent another world war.

In 1947, after nearly two centuries under British colonial rule, India achieved independence. Jawaharlal Nehru, a prominent leader in the Indian independence movement and close associate of Mahatma Gandhi, became the country's first prime minister. Nehru was instrumental in shaping the newly independent India, advocating for secularism, democracy, and modernization. His vision included industrialization, scientific advancement, and a commitment to non-alignment in foreign policy.

In the wake of World War II, the geopolitical landscape was marked by the rising influence of communism, led by the Soviet Union. In 1947, U.S. President Harry S. Truman announced what became known as the Truman Doctrine, a foreign policy designed to contain the spread of communism. The doctrine emerged out of concerns that economically unstable countries, particularly in Europe and Asia, might fall under communist influence.

The 1960s marked a defining era in the United States with the rise of the Civil Rights Movement, which sought to challenge systemic racial inequality and segregation. Leaders like Martin Luther King Jr., Rosa Parks, and countless others organized marches, boycotts, and speeches, advocating for social justice and equality. Major events, such as the March on Washington in 1963 and the Selma to Montgomery marches, underscored the resolve of the movement.

The World Trade Organization (WTO), founded in 1995, was created to regulate international trade and promote fair competition among nations. Building on the General Agreement on Tariffs and Trade (GATT), the WTO aimed to create a framework for resolving trade disputes.

Erected in 1961, the Berlin Wall physically and ideologically divided East and West Berlin, becoming the most prominent symbol of the Cold War era. The German Democratic Republic (East Germany), with the backing of the Soviet Union, constructed the wall to prevent East Berliners from fleeing to the more prosperous West Berlin. Beyond its physical barriers, the Berlin Wall represented the ideological chasm between communist and capitalist systems. For nearly three decades, it stood as a reminder of the world's divisions.

The 1981 release of the IBM Personal Computer (IBM PC) marked a pivotal moment in technology, reshaping the concept of computing for both individuals and businesses. Before this, computers were primarily large, costly systems accessible only to corporations and institutions. IBM's PC was the first to employ a new open architecture model, meaning components were standardized and accessible, allowing other companies to produce compatible parts. The IBM PC became the benchmark for personal computing.

In the aftermath of World War II, much of Europe lay in ruins, with economies devastated, infrastructure destroyed, and populations struggling to rebuild. The Marshall Plan, officially known as the European Recovery Program, was a groundbreaking initiative proposed by the United States in 1948 to assist Western European nations in recovery. Spearheaded by U.S. Secretary of State George C. Marshall, the plan provided over $13 billion in economic aid, targeting countries at risk of succumbing to communist influence amid widespread poverty and instability.

Signed in 1992, the Treaty of Maastricht officially established the European Union (EU), laying the foundation for economic and political integration among European nations. The treaty introduced the Euro as a common currency.

The Universal Declaration of Human Rights, adopted by the United Nations General Assembly in 1948, established a universal standard for human rights. Drafted in response to the atrocities of World War II, the declaration outlined fundamental rights and freedoms that should be guaranteed to all individuals.

The Kyoto Protocol, signed in 1997, was an international treaty aimed at reducing greenhouse gas emissions to combat climate change. Recognizing that industrialized nations were largely responsible for rising emissions, the protocol set binding targets for these countries to decrease their carbon output.

Nelson Mandela, a central figure in South Africa's anti-apartheid movement, spent 27 years in prison for his opposition to the government's racial segregation policies. Mandela's resilience and commitment to justice made him an international symbol of resistance to apartheid.

The fall of the Berlin Wall in 1989 is often cited as a key event leading to the end of the Soviet Union. This moment symbolized the collapse of communist control in Eastern Europe, as citizens from East and West Berlin reunited after decades of separation.

The North Atlantic Treaty Organization (NATO) was established in 1949 as a military alliance to counter the perceived threat posed by the Soviet Union. Based on principles of collective defense, NATO's founding members pledged to protect one another in case of an armed attack against any member.

In 1957, the Soviet Union launched Sputnik, the first artificial satellite, into Earth's orbit. This groundbreaking event marked the beginning of the Space Race, an era of intense competition between the United States and the Soviet Union for dominance in space exploration.

Martin Luther King Jr. became a prominent leader in the Civil Rights Movement during the 1950s and 1960s, advocating for equality and social justice through nonviolent resistance. Known for his powerful speeches, his 'I Have a Dream' speech, delivered during the 1963 March on Washington, has become one of the most iconic calls for racial equality.

On June 6, 1944, Allied forces launched Operation Overlord, known as the D-Day invasion, in Normandy, France. The objective of this operation was to establish a stronghold in Nazi-occupied Western Europe, providing a foothold to advance into German-occupied territories. D-Day was a massive undertaking involving more than 156,000 American, British, and Canadian troops.

Signed in 1994, the North American Free Trade Agreement (NAFTA) was designed to eliminate trade barriers between the United States, Canada, and Mexico, creating one of the largest free-trade zones in the world. NAFTA aimed to enhance economic cooperation by removing tariffs and promoting cross-border investment.

The early 20th century was a period of immense tension among European powers, characterized by military build-up, intense nationalism, and complex alliances. On June 28, 1914, Archduke Franz Ferdinand of Austria-Hungary was assassinated in Sarajevo by Gavrilo Princip, a Bosnian Serb nationalist. This event, though seemingly isolated, triggered a chain reaction among nations bound by treaties and allegiances. Austria-Hungary, backed by Germany, saw an opportunity to address longstanding conflicts in the Balkans, while Russia aligned with Serbia. This cascade of alliances and political maneuvers led to the rapid escalation from regional tensions to global warfare.