Dashed left edge = started before October 1780 ·
Dashed right edge = ongoing beyond October 1780
Events in October 1780 4
1780Massachusetts Constitution ratifiedOldest functioning written constitution in the worldDrafted largely by John Adams, the Massachusetts Constitution was approved by voters in June. It took effect in October. It remains in force today.
1780Arnold's treason at West PointBenedict Arnold's plot is exposed and he defectsBenedict Arnold, commander at West Point, arranged to surrender the fort to the British through Major John Andre. Andre was captured on 23 September carrying incriminating papers, and Arnold fled to British lines. Andre was hanged as a spy on 2 October.
1780Battle of Kings MountainPatriot militia destroy a Loyalist forcePatriot frontier militia surrounded and defeated a Loyalist detachment under Patrick Ferguson on a ridge in South Carolina. Ferguson was killed and most of his command killed or captured. The victory checked Cornwallis's advance into North Carolina.
1780Great Hurricane of 1780Deadliest Atlantic hurricane on recordThe hurricane struck the eastern Caribbean in October, devastating Barbados, Martinique and St. Lucia. An estimated 22,000 or more people died. British and French fleets were badly damaged during the war.