April 8, 1780 – At Charleston, South Carolina, the British attack begins as warships sail past the cannons of Fort Moultrie and enter Charleston harbor. General George Washington sends reinforcements.
April 14, 1780 – Lieutenant Colonel Banastre Tarleton scattered American militia at Monck’s Corner, South Carolina.
May 6, 1780 – The British capture Fort Moultrie at Charleston, South Carolina.
May 6, 1780 – Lieutenant Colonel Banastre Tarleton dispersed American cavalry at Lenud’s Ferry, South Carolina.
May 12, 1780 – The worst American defeat of the Revolutionary War occurs as the British capture Charleston, South Carolina and the entire southern American Army along with four ships and a military arsenal. British losses are only 225.
May 25, 1780 – After a severe winter, General George Washington faces a serious threat of mutiny at his winter camp in Morristown, New Jersey. Two Continental regiments conduct an armed march through the camp and demand immediate payment of salary, which is overdue by five months, and full rations. Troops from Pennsylvania put down the rebellion and two of the leaders of the protest were hanged.
May 29, 1780 – Lieutenant Colonel Banastre Tarleton and his Loyalist Legion bayoneted 113 Continental soldiers of Colonel Buford’s Virginia unit at Waxhaws, South Carolina. Known as Buford’s Massacre.
June 5, 1780 – Lord Charles Cornwallis assumes command of the British Army in the South.
June 11, 1780 – A new Massachusetts constitution is endorsed asserting “all men are born free and equal,” which includes black slaves.
July 11, 1780 – Six Thousand French soldiers under Count de Rochambeau arrive at Newport, Rhode Island. They will remain there for nearly a year, blockaded by the British fleet.
June 13, 1780 – General Horatio Gates is commissioned by Congress to command the Southern Army.
June 20, 1780 – At Ramsour’s Mill, North Carolina, Patriot forces defeated Loyalist forces, ultimately resulting in loss of Loyalist support in the colony.
June 23, 1780 – American forces defeat the British in the Battle of Springfield, New Jersey.
July 12, 1780 – At Williamson’s Plantation, South Carolina, Patriot forces of Thomas Sumter’s command defeated Loyalist Christian Huck and his forces. Huck was killed.
July 12, 1780 – At Cedar Springs, South Carolina, a spartan regiment of Patriots ambushed Loyalist attacking party.
July 13, 1780 – At Gowen’s Old Fort, South Carolina, Georgia Patriots attacked a Loyalist camp and defeated them.
July 25, 1780 – General Horatio Gates assumes command of Southern Continental Army.
July 30, 1780 – At Rocky Mount, South Carolina, Thomas Sumter’s troops attacked British post but were forced to withdraw.
July 30, 1780 – At Hanging Rock I, South Carolina, North Carolina Royalists were attacked by North Carolina Patriots who succeeded in capturing weapons and horses.
August 3, 1780 – Benedict Arnold is appointed commander of West Point. Unknown to the Americans, he has been secretly collaborating with British General Henry Clinton since May, 1779 by supplying information on General George Washington’s tactics.
August 6, 1780 – At Hanging Rock II, South Carolina, Thomas Sumter attacked British post and inflicted heavy casualties but was forced to retreat.
Aug 15, 1780 – At Kershaw County, South Carolina, Patriot militia attacked and captured Carey’s Fort and took a supply convoy from Ninety-Six.
Aug 16, 1780 – In the Battle of Camden, South Carolina, Major General Horatio Gates and the Continental Army were badly defeated by Lord Charles Cornwallis and the British forces.
Aug.18, 1780 – At Fishing Creek, South Carolina, Lieutenant Colonel Banastre Tarleton surprised Thomas Sumter’s command and defeated it.
August 18, 1780 – At Musgrove’s Mill, South Carolina, frontier riflemen and militiamen lured the British into an ambush and defeated them.
August 25, 1780 – At Nelson’s Ferry, South Carolina, Francis Marion attacked a British convoy and released 150 Americans who had been taken prisoner at the Battle of Camden.
September 4, 1780 – At Blue Savannah, South Carolina, Francis Marion led British Loyalists into an ambush and defeated them.
September 14-18, 1780 – Elijah Clarke attacked McKay’s Trading Post, in Georgia but, was driven off when British relief column arrived. American prisoners taken were hanged or turned over to the Cherokee to be tortured and killed.
September 21, 1780 – Lieutenant Colonel Davie attacked Banastre Tarleton at Wahab’s Plantation, North Carolina and captured horses and equipment.
September 23, 1780 – A British major in civilian clothing is captured near Tarrytown, New York. He is found to be carrying plans indicating Benedict Arnold intends to turn traitor and surrender West Point. Two days later, Arnold hears of the spy’s capture and flees West Point to the British ship Vulture on the Hudson River. He is later named a brigadier general in the British Army and will fight the Americans.