Traditionally a celebration for those of Irish heritage, St. Patrick’s Day gained even greater significance in American history when it coincided with a pivotal moment in the Revolutionary War—the British evacuation of Boston. On a day dedicated to Ireland’s patron saint, legendary for banishing the island’s snakes to the sea, American patriots drove British troops from their shores, cheering as they retreated on March 17, 1776.
The eviction of the British after the 11-month Siege of Boston marked a crucial step toward American independence and earned George Washington his first major strategic victory since assuming command of the Continental Army in July 1775 thanks to planning, patience and a little luck of the Irish.
The Patriots Fortify Dorchester Heights
As the Siege of Boston that followed the Battles of Lexington and Concord lingered into the winter of 1776, Washington’s frustration grew. Eager to break the stalemate by launching an attack over the frozen waterways surrounding the city, the Continental Army commander spent his mornings jumping on the ice to assess its strength. Hungry for a battlefield confrontation, Washington asserted that a “stroke well aimed at this critical juncture might put a final end to the war.”
Heeding the advice of his generals, who rejected a direct strike on the heavily defended city as too risky, Washington agreed to a back-up plan to fortify unoccupied Dorchester Heights, perched 112 feet high to the south of Boston, with some of the 59 cannons hauled from Fort Ticonderoga by Henry Knox’s expedition.
To divert British attention from their movements south of the city, Washington ordered a thunderous artillery attack from the north on March 2, 1776. On the barrage’s third night, approximately 2,000 colonial soldiers and volunteers, along with hundreds of oxcarts, hauled cannons and makeshift fortifications up the twin hills of Dorchester Heights. The fierce bombardment drowned out the sound of patriots felling trees and assembling enormous wooden scaffolds for defenses, as the frozen ground made digging trenches and breastworks impossible.
British Are Taken by Surprise
The British awoke on the morning of March 5 startled to find themselves within range of at least 20 cannons atop Dorchester Heights. “My God, these fellows have done more work in one night than I could make my army do in three months,” proclaimed General William Howe, the British army’s commander in chief in America.
“The British underestimated the rebels because they lacked artillery and thought they weren’t that much of a threat, so it catches them by surprise,” says Suffolk University history professor Robert Allison. One British officer thought the fortifications must have been raised by “an expedition equal to that of the genie belonging to Aladdin’s wonderful lamp.”
Although Howe had considered abandoning Boston for months, he ordered 2,000 troops to launch an amphibious attack on Dorchester Heights that could have proved even bloodier than the Battle of Bunker Hill. Nature, however, proved an overpowering foe. A March storm that pelted the Redcoats with hail, sleet, driving rain and gale-force winds, drove three transport ships aground and prevented a British landing. “That this remarkable interposition of Providence was designed to answer some wise purpose I have no doubt,” wrote Washington of the fortuitous storm.
As the colonists further strengthened Dorchester Heights, Howe ordered the evacuation of Boston and sent word to Washington that he had “no intention of destroying the town, unless the troops under his command are molested during the embarkation.”
On the morning of March 17, the eight-year occupation of Boston by British troops ended as a 120-ship fleet set sail with 1,100 loyalists and nearly 11,000 Redcoats and their families.
“The more I think of our enemies quitting Boston, the more amazed I am,” wrote future first lady Abigail Adams. “That we should be in peaceable possession of a town which we expected would cost us a river of blood without one drop shed, surely it is the Lord’s doings and it is marvelous in our eyes.”
“It’s the first American victory in the war for independence,” Allison says. “But this is in many ways Massachusetts’s independence day because the war had begun as a way of keeping them in line with British policy.”
Washington Cedes Place of Honor
Rather than leading the first patriot troops into the newly liberated city, Washington instead gave that honor to General Artemas Ward, commander of the Massachusetts militia and an early champion of the Dorchester Heights plan.
“Washington has an extraordinary political understanding of the role he’s playing, so he doesn’t enter Boston as the general who forced out the British,” Allison says. “By having Ward go in first, Washington shows that this isn’t one army replacing another, but the civilian power of Massachusetts retaking its capital.”
Led by Ward on horseback, 500 colonial soldiers triumphantly marched into Boston on the afternoon of March 17 with Washington entering the city the following day. By month’s end, much of the Continental Army had departed Boston for the next theater of war—New York City—where Howe eventually sailed with his regrouped army after depositing the evacuated loyalists in Halifax, Nova Scotia.
March 17 Becomes Dual Boston Holiday
Native-born Irish and descendants of Irish immigrants, such as Knox and General John Sullivan, played key roles in the Siege of Boston and the first phase of the Revolutionary War. Approximately 200 militiamen who were born in Ireland participated in the Battle of Bunker Hill, where at least 26 lost their lives.
Washington acknowledged the extra pride felt by the Irish at the St. Patrick’s Day ouster of the British, who ruled both Ireland and America at the time. According to the General Orders issued on March 17, 1776, anyone wishing to pass the sentries guarding the Continental Army camp that day needed to give a special password—“St. Patrick.”
Decades later, the South Boston neighborhood that sprouted around Dorchester Heights happened to grow into one of the most Irish American in the country. While St. Patrick’s Day evolved into an unofficial holiday to revel in all things Irish, Evacuation Day became a legal civic holiday in Boston starting in 1901, giving the city two reasons to celebrate March 17 every year.
