On This Day in History: September 9

Across the centuries, September 9 has served as a backdrop for notable political transformations, technological curiosities, and dramatic wartime encounters. Here is a chronological look at ten verified historical events that took place on this day.

1087 — Death of King William I (William the Conqueror)

On September 9, 1087, King William I of England, widely remembered as William the Conqueror, died in Rouen, France. William had sustained severe internal injuries weeks earlier when his horse stumbled during the siege and burning of the French town of Mantes. Following his death, his remains were transported to the abbey church of Saint-Étienne in Caen, Normandy, for burial.

1776 — The Continental Congress Officially Adopts the Name "United States of America"

On September 9, 1776, the Second Continental Congress meeting in Philadelphia passed an official resolution establishing the name of the new nation. The declaration ordered that in all continental commissions and formal instruments where the term "United Colonies" had previously been used, the wording be formally changed to the "United States" of America.

1850 — California Admitted as the 31st U.S. State

On September 9, 1850, United States President Millard Fillmore signed into law the admission of California into the Union as the 31st state. Coming as part of the broader Compromise of 1850 negotiated in the U.S. Congress, California entered directly as a free state without ever first going through formal territorial status, spurred heavily by the rapid population influx of the 1849 Gold Rush.

1919 — The Boston Police Strike Begins

On September 9, 1919, roughly three-quarters of the Boston Police Department walked off the job after the city's police commissioner suspended nineteen officers for attempting to affiliate with the American Federation of Labor. The resulting lack of a police presence led to immediate civil unrest, prompting Massachusetts Governor Calvin Coolidge to call out the state militia to restore public order, an action that elevated Coolidge to national political prominence.

1942 — First Japanese Air Raid on the Contiguous U.S. Mainland

On September 9, 1942, during World War II, a Japanese naval floatplane conducted the first aerial bombing of the contiguous United States mainland. Warrant Flying Officer Nobuo Fujita launched his Yokosuka E14Y aircraft from the submarine I-25 off the Pacific coast and dropped incendiary bombs onto Mount Emily near Brookings, Oregon, aiming to ignite large forest fires, though rapid response by local forest lookouts quickly extinguished the blazes.

1947 — Technicians Find the First Literal Computer "Bug"

On September 9, 1947, engineers working on the electromechanical Mark II Aiken Relay Calculator at Harvard University discovered a live moth trapped between relays, which was causing the machine to malfunction. Led by operator William Burke and computer pioneer Grace Hopper, the team removed the insect and taped it into their daily logbook with the notation: "First actual case of bug being found."

1971 — The Attica Prison Uprising Begins in New York

On September 9, 1971, more than 1,200 incarcerated men seized control of the maximum-security Attica Correctional Facility in western New York. Holding thirty-nine correctional officers and civilian staff as hostages, the prisoners issued demands concerning living conditions, medical care, and legal rights, setting off a four-day standoff that ended on September 13 when state authorities ordered an armed retaking of the compound.

1976 — Death of Chinese Leader Mao Zedong

On September 9, 1976, Chairman Mao Zedong, the primary founding father of the People's Republic of China and head of the Chinese Communist Party since 1949, passed away in Beijing at the age of eighty-two. His death closed the era of the Cultural Revolution and opened the way for significant political and economic shifts throughout the country under subsequent leadership.

1990 — Pete Sampras Wins His First Grand Slam Singles Title

On September 9, 1990, nineteen-year-old American tennis player Pete Sampras defeated fellow countryman Andre Agassi in straight sets (6–4, 6–3, 6–2) to win the U.S. Open men's singles championship in Flushing Meadows, New York. The victory marked Sampras's first career Grand Slam title, making him the youngest male champion in the history of the U.S. Open tournament.

2001 — Assassination of Afghan Commander Ahmad Shah Massoud

On September 9, 2001, Ahmad Shah Massoud, the military leader of the anti-Taliban United Islamic Front (Northern Alliance), was assassinated in Khwaja Bahauddin in Takhar Province, Afghanistan. Two attackers posing as Belgian television journalists detonated explosives hidden inside their video camera equipment, fatally wounding the commander just two days prior to the September 11 terrorist attacks in the United States.