September 17 in History

The American Revolutionary War, also known as the Revolutionary War or American War of Independence, was the armed conflict that comprised the final eight years of the broader American Revolution, in which American Patriot forces organized as the Continental Army and commanded by George Washington defeated the British Army. The conflict was fought in North America, the Caribbean, and the Atlantic Ocean. The war's outcome seemed uncertain for most of the war, but Washington and the Continental Army's decisive victory in the Siege of Yorktown in 1781 led King George III and the Kingdom of Great Britain to negotiate an end to the war. In 1783, in the Treaty of Paris, the British monarchy acknowledged the independence of the Thirteen Colonies, leading to the establishment of the United States as an independent and sovereign nation.

The Treaty of Fort Pitt, also known as the Treaty With the Delawares, the Delaware Treaty, or the Fourth Treaty of Pittsburgh, was signed on September 17, 1778; it was the first formal treaty between the new United States of America and any Native American groups, in this case the Lenape, called the Delaware by white settlers. Although there were informal agreements between Native Americans and the Americans during the American Revolutionary War, the first one that resulted in a formal document was signed at Fort Pitt, Pennsylvania, now the site of Downtown Pittsburgh. It was essentially a treaty of military alliance between the Lenape Nation and the United States.

The War of the Pyrenees, also known as War of Roussillon or War of the Convention, was the Pyrenean front of the First Coalition's war against the First French Republic. It pitted Revolutionary France against the kingdoms of Spain and Portugal from March 1793 to July 1795 during the French Revolutionary Wars.

The Finnish War was fought between the Kingdom of Sweden and the Russian Empire from 21 February 1808 to 17 September 1809 as part of the Napoleonic Wars. As a result of the war, the eastern third of Sweden was established as the autonomous Grand Duchy of Finland within the Russian Empire. Other notable effects were the Swedish parliament's adoption of a new constitution and the establishment of the House of Bernadotte, the new Swedish royal house, in 1818.

Joshua Abraham Norton was a resident of San Francisco, California, who in 1859 declared himself "Emperor of these United States" in a proclamation that he signed "Norton I., Emperor of the United States". Commonly known as Emperor Norton, he took the secondary title "Protector of Mexico" in 1866.

The American Civil War was a civil war in the United States between the Union and the Confederacy, which was formed in 1861 by states that had seceded from the Union to preserve slavery in the United States, which they saw as threatened because of the election of Abraham Lincoln and the growing abolitionist movement in the North. The war lasted a little over four years, ending with Union victory, the dissolution of the Confederacy and the abolition of slavery, freeing four million African Americans.

The Battle of the Yalu River was the largest naval engagement of the First Sino-Japanese War, and took place on 17 September 1894, the day after the Japanese victory at the land Battle of Pyongyang. The Imperial Japanese Navy defeated the Chinese Beiyang Fleet.

The Second Boer War, also known as the Boer War, Transvaal War, Anglo–Boer War, or the South African War, was a conflict fought between the British Empire and the Boer republics over Britain's influence in Southern Africa.

The Wright Flyer made the first sustained flight by a manned heavier-than-air powered and controlled aircraft on December 17, 1903. Invented and flown by brothers Orville and Wilbur Wright, it marked the beginning of the pioneer era of aviation.

World War I, or the First World War, also known as The Great War, was a global conflict between two coalitions: the Allies and the Central Powers. Major areas of conflict included Europe and the Middle East, as well as parts of Africa and the Asia-Pacific. The war saw important developments in weaponry including tanks, aircraft, artillery, machine guns, and chemical weapons. One of the deadliest conflicts in history, it resulted in an estimated 15 to 22 million military and civilian casualties and genocide. The movement of large numbers of people was a major factor in the deadly Spanish flu pandemic.

The National Football League (NFL) is a professional American football league in the United States. Composed of 32 teams, it is divided equally between the American Football Conference (AFC) and the National Football Conference (NFC). The NFL is one of the major professional sports leagues in the United States and Canada and the highest professional level of American football in the world. Each NFL season begins annually with a three-week preseason in August, followed by an 18-week regular season, which runs from early September to early January, with each team playing 17 games and having one bye week. Seven teams from each conference, including the four division winners and three wild card teams, then advance to the playoffs, a single-elimination tournament, which culminates in the Super Bowl, played in early February between the winners of the AFC and NFC championship games. The NFL is headquartered in New York City.

The Okeechobee hurricane of 1928, also known as the San Felipe Segundo hurricane and Florida's Forgotten Storm, was one of the deadliest hurricanes in the recorded history of the North Atlantic basin, and the fourth deadliest hurricane in the United States, only behind the 1900 Galveston hurricane, 1899 San Ciriaco hurricane, and Hurricane Maria in 2017. The hurricane killed an estimated 2,500 people in the United States; most of the fatalities occurred in the state of Florida, particularly around Lake Okeechobee. It was the fourth tropical cyclone, third hurricane, and only major hurricane of the 1928 Atlantic hurricane season, and remains the deadliest disaster in Florida's history to date. It developed off the west coast of Africa on September 6 as a tropical depression, but it strengthened into a tropical storm later that day, shortly before passing south of the Cape Verde islands. Further intensification was slow and halted late on September 7. About 48 hours later, the storm strengthened and became a Category 1 hurricane on the Saffir–Simpson hurricane wind scale. Still moving westward, the system reached Category 4 intensity before striking Guadeloupe on September 12, where it brought great destruction and resulted in 1,200 deaths. The islands of Martinique, Montserrat, and Nevis also reported damage and fatalities, but not nearly as severe as in Guadeloupe.

Laureano Eleuterio Gómez Castro was a Colombian politician and civil engineer who served as President of Colombia from 1950 to 1953. In November 1951 poor health led him to cede presidential power to Roberto Urdaneta Arbeláez. On 13 June 1953, when he tried to resume his presidency, he was overthrown in a military coup led by Gustavo Rojas Pinilla.

World War II, or the Second World War, was a global conflict between two coalitions: the Allies and the Axis powers. Nearly all of the world's countries participated. Tanks and aircraft played major roles, the latter enabling the strategic bombing of cities and delivery of the only nuclear weapons used in war. World War II was the deadliest conflict in history, causing the death of 60 to 75 million people. Millions died as a result of massacres, starvation, disease, and genocides, including the Holocaust. After the Allied victory, Germany, Austria, Japan, and Korea were occupied, and German and Japanese leaders were tried for war crimes.

The Battle of Britain was a military campaign of the Second World War, in which the Royal Air Force (RAF) and the Fleet Air Arm (FAA) of the Royal Navy defended the United Kingdom against large-scale attacks by Nazi Germany's air force, the Luftwaffe. It was the first major military campaign fought entirely by air forces. It takes its name from the speech given by Prime Minister Winston Churchill to the House of Commons on 18 June, 1940: "What General Weygand called the 'Battle of France' is over. I expect that the Battle of Britain is about to begin."

The Anglo-Soviet invasion of Iran, also known as the Anglo-Soviet invasion of Persia or the Allied invasion of Iran, was the joint invasion of the officially neutral Imperial State of Iran by the United Kingdom and the Soviet Union in August 1941. The two powers announced that they would stay until six months after the end of the war with their mutual enemy, Nazi Germany, which turned out to be 2 March 1946. On that date the British began to withdraw, while the Soviet Union delayed until May, initially citing "threats to Soviet security", followed by the Iran crisis of 1946.

The Tallinn offensive was a strategic offensive by the Red Army's 2nd Shock Army and 8th Army and the Baltic Fleet against the German Army Detachment Narwa and Estonian units in mainland Estonia on the Eastern Front of World War II on 17–26 September 1944. Its German counterpart was the abandonment of the Estonian territory in a retreat codenamed Operation Aster.

Lehi, officially the Fighters for the Freedom of Israel and often known pejoratively as the Stern Gang, was a Zionist paramilitary militant organization founded by Avraham ("Yair") Stern in Mandatory Palestine. Its avowed aim was to evict the British authorities from Palestine by use of violence, allowing unrestricted immigration of Jews and the formation of a Jewish state. It was initially called the National Military Organization in Israel, upon being founded in August 1940, but was renamed Lehi one month later. The group referred to its members as terrorists and admitted to having carried out acts of terrorism.

SS Noronic was a Canadian passenger ship that was destroyed by fire in Toronto Harbour in September 1949 with the loss of at least 118 lives.

The Civic Arena, formerly the Civic Auditorium and later Mellon Arena, was an arena located in Downtown Pittsburgh, Pennsylvania. The Civic Arena primarily served as the home to the Pittsburgh Penguins, the city's National Hockey League (NHL) franchise, from 1967 to 2010.

The Battle of Chawinda was a major engagement between Pakistan and India during the Indo-Pakistani war of 1965 as part of the Sialkot campaign. It is well known as being one of the largest tank battles in history since the Battle of Kursk, which was fought between the Soviet Union and Nazi Germany in World War II.

Space Shuttle Enterprise is the first orbiter of the Space Shuttle system. Rolled out on September 17, 1976, it was built for NASA as part of the Space Shuttle program to perform atmospheric test flights after being launched from a modified Boeing 747. It was constructed without engines or a functional heat shield. As a result, it was not capable of spaceflight.

The Gdańsk Shipyard is a large Polish shipyard, located in the city of Gdańsk, northern Poland. The yard gained international fame when Polish trade union Solidarity was founded there in September 1980. It is situated on the western side of Martwa Wisła and on Ostrów Island.

Vanessa Lynn Williams is an American singer, actress, model, producer and dancer. She gained recognition as the first black woman to win the Miss America title when she was crowned Miss America 1984. She would later resign her title amid a media controversy surrounding nude photographs published in Penthouse magazine. 32 years later, Williams was offered a public apology during the Miss America 2016 pageant for the events.

Linux is a family of open source Unix-like operating systems based on the Linux kernel, a kernel first released on 17 September 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which includes the kernel and supporting system software and libraries – most of which are provided by third parties – to create a complete operating system. Linux was originally designed as a clone of Unix and is released under the copyleft GPL license.

The New York Stock Exchange is an American stock exchange headquartered at the New York Stock Exchange Building in the Financial District of Lower Manhattan in New York City. It is the largest stock exchange in the world by market capitalization, exceeding $44 trillion in January 2026. The NYSE is owned by Intercontinental Exchange, an American holding company that it also lists. Previously, it was part of NYSE Euronext (NYX), which was formed by the NYSE's 2007 merger with Euronext. According to a Gallup poll conducted in 2022, approximately 58% of American adults reported having money invested in the stock market, either through individual stocks, mutual funds, or retirement accounts.

Fourpeaked Mountain, also known as Fourpeaked Volcano, is an active stratovolcano located in the U.S. state of Alaska within Katmai National Park and Preserve. The volcano is nearly completely covered by Fourpeaked Glacier.

Occupy Wall Street (OWS) was a left-wing populist and progressive movement against economic inequality, capitalism, corporate greed, big finance, and the influence of money in politics. It began in Zuccotti Park, located in New York City's Financial District, and lasted for fifty-nine days—from September 17 to November 15, 2011.

On 17 September 2018, the Israeli Air Force (IAF) conducted missile strikes against multiple targets in government-controlled western Syria. Syrian air defences responded to the Israeli fighter jets, accidentally shooting a Russian military Il-20, killing 15 crew aboard. Russia blamed Israel for the loss of its plane, accusing the IAF of "hiding behind the Russian aircraft", thereby putting it in the line of fire. The Israel Defense Forces acknowledged striking a Syrian weapons facility, and expressed sorrow for the loss of lives due to Syrian fire. The strikes occurred a few hours after a Russo-Turkish agreement to create a demilitarized zone around Idlib Governorate was achieved, which postponed an imminent offensive operation by Syria's forces and its allies.