March 21

The Napoleonic Code is formally adopted as French civil law, later influencing legal systems across much of the world.

Napoleon Bonaparte promulgated the French Civil Code, later known as the Napoleonic Code, unifying and modernizing French civil law under principles of equality before the law and secular governance. The code was subsequently adopted or adapted by numerous countries across Europe, Latin America, and beyond.

Otto von Bismarck is appointed the first Chancellor of the newly unified German Empire.

Following the unification of Germany after the Franco-Prussian War, Otto von Bismarck was appointed the first Chancellor of the new German Empire, a position from which he dominated European diplomacy for the next two decades through a complex system of alliances.

Germany launches Operation Michael, the first phase of its major spring offensive on the Western Front.

German forces launched Operation Michael, a massive offensive intended to break through Allied lines before American reinforcements could fully arrive, achieving significant early territorial gains. The offensive ultimately stalled, and the exhausted German army was unable to sustain further large-scale attacks for the rest of the war.

The Hungarian Soviet Republic is proclaimed, becoming the first communist government established in Europe after the Russian Revolution.

Communist revolutionaries led by Bela Kun proclaimed the Hungarian Soviet Republic, the second communist state established anywhere after Soviet Russia itself, following the collapse of the earlier short-lived Hungarian democratic government amid postwar chaos and territorial losses. The radical regime nationalized industry and land but fell within about four months to counter-revolutionary forces and a Romanian military intervention.

South African police open fire on peaceful anti-apartheid demonstrators, killing 69 in the Sharpeville massacre.

South African police opened fire on a crowd of unarmed Black protesters demonstrating against pass laws outside a police station in Sharpeville, killing 69 people and wounding many more. The massacre drew international condemnation and became a pivotal moment galvanizing global opposition to apartheid.

Alcatraz Federal Penitentiary closes permanently.

Alcatraz Federal Penitentiary, the notorious island prison in San Francisco Bay that had housed inmates including Al Capone, closed permanently due to the high cost of maintaining the isolated facility. It later reopened as a popular tourist attraction operated by the National Park Service.

Martin Luther King Jr. leads thousands on the successful third Selma-to-Montgomery civil rights march.

Protected by federal troops after a court order, roughly 25,000 marchers led by Martin Luther King Jr. completed the successful third attempt to march from Selma to Montgomery, Alabama, following the violent suppression of earlier attempts. The march built crucial momentum for the Voting Rights Act.

President Jimmy Carter announces a U.S. boycott of the 1980 Summer Olympics in Moscow, in protest of the Soviet invasion of Afghanistan.

President Jimmy Carter announced that the United States would boycott the upcoming Moscow Summer Olympics in protest of the Soviet Union's invasion of Afghanistan months earlier, a decision joined by dozens of other nations and one that the Soviet bloc reciprocated by boycotting the 1984 Los Angeles Games.

Namibia becomes independent after decades of South African administration.

Namibia gained full independence from South African administration after a lengthy armed liberation struggle led by the South West Africa People's Organisation and a United Nations-supervised transition process. Sam Nujoma was inaugurated as the country's first president, marking the end of one of Africa's last remaining colonial-era territorial disputes and completing the continent's broader decolonization wave.

The social media platform Twitter is founded.

Jack Dorsey sent the first message on a new microblogging platform he co-founded called Twitter, a simple text reading "just setting up my twttr." What began as a niche status-update tool went on to become one of the most influential social media services in the world for real-time news, public discourse, activism, and political communication over the following decade.