In History, Today on May 18

Finnish President Sauli Niinistö and Swedish Prime Minister Magdalena Andersson met with US President Joe Biden at the White House. The meeting was a part of the process of Finland's and Sweden's efforts to join NATO, seeking to bolster security and military cooperation amidst regional security concerns following Russia’s invasion of Ukraine.

The World Health Organization (WHO) held its 73rd World Health Assembly virtually due to the COVID-19 pandemic, focusing on the global response to the crisis.

A school shooting at Santa Fe High School in Texas results in the deaths of 10 people, marking one of the deadliest school shootings in U.S. history.

A shootout between rival biker gangs in Waco, Texas, results in nine deaths and 18 injuries, leading to the arrest of over 170 individuals.

Facebook holds its initial public offering (IPO), raising $16 billion, making it one of the largest IPOs in technology and Internet history.

Underwater oil leak caused by the Deepwater Horizon spill is capped.

The Sri Lankan Civil War officially ends as the government declares victory over the Liberation Tigers of Tamil Eelam (LTTE), following the death of LTTE leader Velupillai Prabhakaran.

Randy Johnson of the Arizona Diamondbacks pitches a perfect game against the Atlanta Braves, becoming the oldest pitcher in Major League Baseball history to achieve this feat at the age of 40.

Somaliland declares independence from Somalia, though it is not internationally recognized.

The World Health Organization removed homosexuality from the International Classification of Diseases.

Mount St. Helens erupts in Washington state, United States, in one of the most significant volcanic events in U.S. history, causing widespread devastation and loss of life.

The First Legislative Yuan of the Republic of China convened for the first time in Nanking, signaling a new phase for the Nationalist government under Chiang Kai-shek after the Constitution was promulgated in 1947.

The Battle of Monte Cassino, one of the most crucial engagements in the Italian Campaign during World War II, concluded with the capture of Monte Cassino and the town of Cassino by the Allies.

The Bath School disaster occurs in Bath Township, Michigan, when a series of bombs set by school board treasurer Andrew Kehoe explode, killing 38 children and 6 adults in the deadliest school massacre in U.S. history.

The Selective Service Act of 1917 was passed by the United States Congress, authorizing the federal government to raise a national army for service in World War I through conscription.

The United States Supreme Court delivers its decision in Plessy v. Ferguson, upholding the constitutionality of racial segregation under the "separate but equal" doctrine.

The Republican National Convention, held in Chicago, nominated Abraham Lincoln as the party's candidate for the presidency of the United States, which he would go on to win.

The Massachusetts Supreme Judicial Court ruled in Roberts v. Boston, upholding the legality of racially segregated schools in Boston. This decision was later influential in the landmark U.S. Supreme Court case Plessy v. Ferguson in 1896.

The first German National Assembly, known as the Frankfurt Parliament, convenes in Frankfurt am Main, marking a significant moment in the German unification movement.

Napoleon Bonaparte is proclaimed Emperor of the French by the French Senate, marking the transition from the French Consulate to the First French Empire.

Rhode Island passed the first law in North America making slavery illegal.

Playwright Thomas Kyd is arrested in London. His lodgings had been searched, and papers belonging to his former roommate, Christopher Marlowe, were found that brought Kyd under suspicion of heresy.

Portuguese explorer Vasco da Gama reaches the port of Calicut (now Kozhikode) in India, marking the first time a European reached India by sea. This event established a sea route from Europe to Asia, which had profound effects on global trade and the expansion of European empires.

The city of Acre, the last major Crusader stronghold in the Holy Land, falls to the Mamluks, marking the end of Crusader presence in the region.

Henry II of England marries Eleanor of Aquitaine.

A devastating earthquake struck the city of Antioch, causing widespread destruction and loss of life. The earthquake is estimated to have killed around 250,000 people, making it one of the deadliest earthquakes in recorded history.

Constantine the Great announced free distribution of food to the citizens of Constantinople, a gesture to gain favor and support for his new capital.