St. Patrick’s Day is renowned for its green beer and revelry, but on March 17, 1776 the day marked a turning point in the Revolutionary War. Through the course of events, a young bookworm would serendipitously uncover a solution that unlocked American innovation and changed history.
Two months after his initial departure from Fort Ticonderoga, on January 25, 1776, Henry Knox employing 42 sleds miraculously moved 60 tons of captured British artillery 300 miles over snow-draped mountains and across frozen rivers to Cambridge, Massachusetts. With the artillery in hand, Washington renewed his plans for an attack on Boston. But lack of powder and the 8,000-or-more-strong British garrison made the attack very iffy. During a council of war, 49-year-old Major General Artemas Ward presented another plan: “The attack must be made with the view of bringing on an engagement, or of driving the enemy out of Boston and either end will be answered much better by possessing Dorchester Heights.” The heights were less than a mile from Boston, and cannon fire could easily sail over the harbor and hit the city—whoever controlled the heights controlled Boston.
The challenge: how to build a fort atop the heights in the middle of winter before the British stormed the redoubt prior to its completion. Washington would find his answer at one of his dinners. A guest that day was 30-old-year-old Rufus Putnam, who, as a teenager during the French and Indian War, gained just enough knowledge of fieldworks to make him dangerous. During the meal, Washington asked the Braintree native how to build a fortification on frozen ground quickly. Confessing, “I never read a word on the subject . . . but was employed in Some under British Engineers,” he told Washington he’d get back to him since “no excuse would do.” Pondering the question while walking back to his bed, “Singular circumstances I call providence,” Putnam visited General William Heath’s quarters and noticed a book on his table entitled The Attack and Defense of Fortified Places by John Muller, and he asked to borrow it. Heath refused and claimed he never lent his books. Eventually, Heath relented, and Putnam went back to his quarters and fell asleep with the book on his chest. The next morning Putnam found the answer on page 4 in a fortification term he had never heard of “chandeliers.” Running back to Washington’s headquarters, Putnam relayed his astounding finding to the commander in chief. The solution lay in building a series of prefabricated wooden frames five feet high filled with tree branches bundled together that could be quickly transported atop Dorchester Heights and assembled into walls. The walls could later be topped off with earth and embrasures could be formed in the fortification to protect the artillery from Ticonderoga.
This remarkable untold story is in the new bestselling book, The Indispensables: Marblehead’s Diverse Soldier-Mariners Who Shaped the Country, Formed the Navy, and Rowed Washington Across the Delaware. The book is a Band of Brothers-style treatment of this unique group of Americans who changed the course of history.
To the horror of the British, shells started exploding on their positions on March 4, 1776. Knox’s artillerists fired on the city as a diversion for the real attack from Dorchester Heights. Washington wanted the noise created by artillery to cover the construction of the fieldworks on Dorchester.
On the night of March 4, the Americans converged on Dorchester Heights. A full moon illuminated their movements as they quickly seized the high ground with no resistance from the British. American innovation and ingenuity were on full display as 300 teams of wagons loaded with entrenching tools and prefabricated chandeliers, gabions, and fascines (bundles of sticks) formed the bulwark of three fortifications on top of the mount. Hundreds of men bit into the frozen ground with pickaxes and shovels as they put the chandeliers into place and shoveled dirt and rock into the cylindrical gabions. Working like a colony of bees, the men remarkably completed the bulk of the work in about an hour. From Dorchester Heights, the Americans could shell the British positions inside Boston with impunity. As dawn broke over Boston, the horrified British saw the three forts that seemingly materialized out of thin air overnight: “The enemy had thrown three very extensive structures with strong abattis round them on the commanding hills on Dorchester Neck, which must have been the employment of at least 12,000 men.”
William Howe, the commander of the British troops in Boston, immediately responded to the crisis and ordered 2,400 of his men into boats to launch an amphibious assault and storm the heights. This is exactly what Washington hoped for—a frontal assault directly into the teeth of his defenses where the defenders would outnumber the attackers. It would have been a bloodbath. Washington even positioned heavy barrels loaded with dirt and rock the Americans could roll down on the advancing Redcoats. However, as would occur many times during the Revolution, weather would alter history. An enormous storm set in, blowing the boats in the harbor, making it impossible to launch the assault. Howe postponed the attack, but the storm raged until March 6, creating two priceless days for Washington to move in more troops and further strengthen the defenses.
General Howe realized his situation was no longer tenable and decided to evacuate Boston. Terrified to fall into the hands of their fellow Americans, thousands of Loyalists crammed aboard Howe’s ships. They sailed to Halifax, from where they would regroup and receive reinforcements, and Howe would invade New York. But from that day forward, St. Patrick’s Day, March 17, would become known as “Evacuation Day” in Boston.
Patrick K. O’Donnell is a bestselling, critically acclaimed military historian and an expert on elite units. He is the author of twelve books including The Indispensables, featured nationally at Barnes and Noble and Washington’s Immortals, and The Unknowns. O’Donnell served as a combat historian in a Marine rifle platoon during the Battle of Fallujah and speaks often on espionage, special operations, and counterinsurgency. He has provided historical consulting for DreamWorks’ award-winning miniseries Band of Brothers and for documentaries produced by the BBC, the History Channel, and Discovery. PatrickODonnell.com @combathistorian