September15
Early Modern
1620
Culture
Mayflower Sails for the New World
Plymouth, England

After an earlier false start with a leaking companion ship, the Mayflower finally departed Plymouth, England alone, carrying Separatist Puritans and other colonists across the Atlantic. The 66-day crossing was marked by violent storms, cramped conditions below deck, and the death of two passengers, before the ship reached Cape Cod in November, far north of its intended Virginia destination.

Mayflower Sails for the New World
William Halsall · Public domain
19th Century
1810
Politics
The Cry of Independence
Dolores, New Spain (Mexico)

In the early hours before dawn, parish priest Miguel Hidalgo y Costilla gathered his congregation in the small town of Dolores and delivered what became known as the Grito de Dolores. His call to arms against Spanish colonial authority spread rapidly through the Bajío region, drawing tens of thousands of indigenous and mestizo followers within days and launching an eleven-year war that ended Spanish rule in Mexico.

The Cry of Independence
F. María Zapata · Public domain
World Wars Era
1916
World War II
Tanks Enter Warfare
Somme, France

At the Somme, during the Battle of Flers-Courcelette, the British Army deployed 49 Mark I tanks in combat for the first time in history, hoping the armored, tracked vehicles could crush barbed wire and cross trenches that infantry alone could not breach. Mechanical failures and inexperienced crews limited their impact that day, but the tank's debut permanently changed the character of land warfare.

Tanks Enter Warfare
United States Army · Public domain
1938
Computing
HP's Garage Beginning
Palo Alto, California

With an initial investment of $538 and a workshop set up in a one-car garage behind a rented house on Addison Avenue, Bill Hewlett and Dave Packard began the partnership that became Hewlett-Packard. Their first product, an audio oscillator, soon caught the attention of Walt Disney Studios, which purchased eight units for the film Fantasia, giving the fledgling company an early and prestigious customer.

HP's Garage Beginning
LPS.1 · CC0
1940
World War II
Battle of Britain's Decisive Day
London, England

On what became commemorated as Battle of Britain Day, the Royal Air Force flew roughly 630 sorties against waves of German bombers and fighters attacking London. British pilots shot down around 60 German aircraft against the loss of about 26 of their own, a lopsided result that convinced Hitler's high command the Luftwaffe could not achieve the air superiority needed for Operation Sea Lion, the planned invasion of Britain.

Battle of Britain's Decisive Day
Unknown likely ROC. The original uploader was Dapi89 at English Wikipedia.. Later version(s) were uploaded by Hohum at en.wikipedia. · Public domain
1944
World War II
Marines Storm Peleliu
Peleliu, Palau Islands

The 1st Marine Division landed on Peleliu's beaches under intense Japanese fire, beginning an assault that commanders had predicted would take four days but that instead dragged on for over two months. Japanese defenders under Colonel Kunio Nakagawa abandoned the doomed beach defense doctrine of earlier island battles for a new strategy of deep caves and tunnels, inflicting devastating American casualties and making Peleliu one of the war's bloodiest, most controversial fights.

Marines Storm Peleliu
U.S. Navy photo by Mass Communication Specialist 1st Class Carmen O. Hubbs · Public domain
Cold War & Space Age
1958
Politics
Little Rock Central Closed to All
Little Rock, Arkansas

Rather than allow the Little Rock Nine to continue attending the newly integrated Central High School, Governor Orval Faubus signed legislation closing all four of the city's public high schools for the entire 1958-59 school year, an episode locally remembered as the 'Lost Year.' Roughly 3,700 students were locked out of public education as segregationists sought to nullify federal desegregation orders through legislative defiance.

Little Rock Central Closed to All
Ira Wilmer Counts Jr. · Public domain
1959
Politics
Flag Riots Erupt in Panama
Panama Canal Zone

Panamanian students marched into the U.S.-controlled Canal Zone attempting to plant Panama's flag alongside the American one as a symbolic assertion of sovereignty, leading to violent clashes with U.S. police and troops. The unrest, part of a broader wave of nationalist agitation that year, foreshadowed the deadlier 1964 Flag Riots and decades of tension that eventually culminated in the treaties returning the canal to Panama in 1999.

Flag Riots Erupt in Panama
Zscout370 et al. · Public domain