September 06

Battle of the Frigidus: Roman emperor Theodosius I defeats and kills Eugenius the usurper. His Frankish magister militum Arbogast escapes but commits suicide two days later.

In 394 AD, Emperor Theodosius I decisively defeated the usurper Eugenius at the Battle of the Frigidus, securing his rule over the Roman Empire.

Christopher Columbus sails from La Gomera in the Canary Islands, his final port of call before crossing the Atlantic Ocean for the first time.

In 1492, Christopher Columbus departed La Gomera, embarking on his historic first crossing of the Atlantic to the New World.

The Victoria returns to Sanlúcar de Barrameda in Spain, the only surviving ship of Ferdinand Magellan's expedition and the first known ship to circumnavigate the world.

In 1522, the carrack Victoria completed the first circumnavigation of the globe, returning to Spain under Juan Sebastián Elcano.

The Pilgrims sail from Plymouth, England on the Mayflower to settle in North America. (Old Style date; September 16 per New Style date.)

In 1620 (Old Style), the Pilgrims departed Plymouth aboard the Mayflower, beginning their journey to found a new settlement in North America.

Puritans settle Salem, which became part of Massachusetts Bay Colony.

In 1628, a group of Puritan settlers established Salem, becoming one of the first towns in what would become Massachusetts Bay Colony.

Thirty Years' War: In the Battle of Nördlingen, the Catholic Imperial army defeats Swedish and German Protestant forces.

In 1634, the Battle of Nördlingen saw Catholic Imperial forces triumph over Swedish and Protestant armies, shifting momentum in the Thirty Years' War.

American Revolutionary War: The Battle of Groton Heights takes place, resulting in a British victory.

In 1781, British forces under Benedict Arnold captured Fort Griswold at Groton Heights, securing a victory in the American Revolutionary War.

British scientist John Dalton begins using symbols to represent the atoms of different elements.

In 1803, John Dalton introduced a system of symbols to represent chemical atoms, laying groundwork for modern atomic theory.

American Civil War: Forces under Union General Ulysses S. Grant bloodlessly capture Paducah, Kentucky, giving the Union control of the Tennessee River's mouth.

In 1861, Union General Ulysses S. Grant seized Paducah, Kentucky without a fight, securing control of the Tennessee River’s mouth.