Henry Knox Color Guard of the Massachusetts Sons of the American Revolution Commemorates Evacuation Day at Dorchester Heights South Boston Thursday March 11, 2021. The original Evacuation Day took place on March 17, 1776. Evacuation Day remembers the first major American military victory in the American Revolutionary War, which saw the British troops leave Boston on March 17, 1776. General George Washington, who became the United States’ first president, fortified Dorchester Heights by using cannons captured earlier from Fort Ticonderoga. The armies lobbed shells at each other during the movement, with colonists escalating the action on March 4, distracting the British soldiers’ attention. General William Howe, of the British Army, woke up on March 5 that year to find that there were heavy guns aimed at his solders and down at the British fleet. Rather than repeat the heavy casualties of the Battle of Bunker Hill, the British troops left in haste on March 17 and never returned. This was a major psychological victory for General Washington and the colonists. The American Continental Army’s sacrifices and efforts played a big role in establishing what is known today as the United States of America. The Evacuation Day holiday was proclaimed in 1901 after a failed attempt in 1876.