On this day: 19 June

The original Nicene Creed is adopted at the First Council of Nicaea.

Byzantine forces loyal to emperor Basil II under Bardas Phokas the Younger defeat rebel forces under Bardas Skleros in the battle of Pankaleia (approximate date).

The proprietors of King's Chapel, Boston, voted to adopt James Freeman's Book of Common Prayer, thus establishing the first Unitarian church in the Americas.

War of the Second Coalition: Battle of Höchstädt results in a French victory over Austria.

Battle of Seven Oaks between North West Company and Hudson's Bay Company, near Winnipeg, Manitoba, Canada.

Decisive defeat of the Filiki Eteria by the Ottomans at Drăgășani (in Wallachia).

The Maryland province of the Jesuits contracted to sell 272 slaves to buyers in Louisiana in one of the largest slave sales in American history.

The first officially recorded baseball game in U.S. history using modern rules was played in Hoboken, New Jersey, with the "New York Nine" defeating the New York Knickerbockers 23–1.

The first officially recorded, organized baseball game is played under Alexander Cartwright's rules on Hoboken, New Jersey's Elysian Fields with the New York Base Ball Club defeating the Knickerbockers 23–1. Cartwright umpired.

Princess Louise of the Netherlands marries Crown Prince Karl of Sweden–Norway.

President Abraham Lincoln signs the Territorial Slavery Act of 1862, which prohibits slavery in all current and future United States territories.

Over two years after the Emancipation Proclamation, slaves in Galveston, Texas, United States, are officially informed of their freedom. The anniversary was officially celebrated in Texas and other states as Juneteenth. On June 17, 2021, Juneteenth officially became a federal holiday in the United States.

The Herzegovinian rebellion against the Ottoman Empire begins.

The first Father's Day is celebrated in Spokane, Washington.

Natives Land Act, 1913 in South Africa implemented.

King Roger, an opera about Roger II of Sicily by Karol Szymanowski (pictured), was premiered at the Grand Theatre in Warsaw.

The Communications Act of 1934 establishes the United States' Federal Communications Commission (FCC).

American baseball player Lou Gehrig (pictured) was diagnosed with amyotrophic lateral sclerosis, now commonly known in the United States as "Lou Gehrig's disease".

The Philadelphia Eagles and Pittsburgh Steelers of the NFL merge for one season due to player shortages caused by World War II.

Charlotte Motor Speedway holds its first NASCAR race, the inaugural World 600.

Kuwait declares independence from the United Kingdom.

The Civil Rights Act of 1964 is approved after surviving an 83-day filibuster in the United States Senate.

Nguyễn Cao Kỳ, the commander of the South Vietnam Air Force, was appointed prime minister at the head of a military regime.

The international Patent Cooperation Treaty was signed, providing a unified procedure for filing patent applications to protect inventions in each of its contracting states.

Garfield's first comic strip, originally published locally as Jon in 1976, goes into nationwide syndication.

The People's Armed Police is de facto founded; it is officially established 10 months later on April 5, 1983.

Members of the Revolutionary Party of Central American Workers, dressed as Salvadoran soldiers, attack the Zona Rosa area of San Salvador.

The current international law defending indigenous peoples, Indigenous and Tribal Peoples Convention, 1989, is ratified for the first time by Norway.

The Communist Party of the Russian Soviet Federative Socialist Republic is founded in Moscow.

The last Soviet army units in Hungary are withdrawn.

Only six race cars competed in the United States Grand Prix at the Indianapolis Motor Speedway in Indianapolis, Indiana, after all the Michelin-shod entrants were withdrawn due to safety concerns.

The royal wedding of Victoria, Crown Princess of Sweden, and Daniel Westling took place in Stockholm Cathedral.

The 10,000,000th United States Patent is issued.