In the winter of 1776, a 25-year-old Boston bookseller reported to Gen. George Washington in Cambridge, Massachusetts, with news that would change the course of the Revolutionary War. Col. Henry Knox had just completed what historians call one of the most stupendous feats of logistics in American military history, hauling 60 tons of captured British artillery 300 miles through winter wilderness to break the siege of Boston.
The journey that Knox estimated would take 16 or 17 days had taken 40. But not a single cannon was lost.
An Impossible Proposition
In fall 1775, the Continental Army had Boston under siege but lacked the heavy artillery needed to dislodge British forces. Washington's ragtag troops occupied high ground from which they could theoretically shell the British, but they had virtually no regular artillery company and only a few unserviceable field pieces left behind by retreating enemy troops.
Knox, whose Boston bookshop had been known as a fashionable morning lounge counting John Adams among its regulars, had taught himself military science through voracious reading. After Lexington and Concord, he and his wife Lucy snuck out of Boston in disguise to join the Continental Army.
Now Knox approached Washington with a bold plan. When Ethan Allen's Green Mountain Boys captured Fort Ticonderoga in May 1775, they seized 200 cannons. Most officers thought moving the guns from Lake Champlain to Boston was impossible. Knox thought otherwise.
Washington was so impressed with Knox's energy, ingenuity and knowledge of artillery that on Nov. 16, 1775, Washington gave Knox the assignment with a simple directive: "No trouble or expense must be spared to obtain them."
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Selecting the Arsenal
Knox reached Fort Ticonderoga on Dec. 5, 1775. Working with the garrison, he selected 59 artillery pieces for the 250-mile trek: 43 heavy brass and iron cannons, eight mortars, six cohorns (a lightweight type of mortar), and two howitzers. Most were 12-pounder or 18-pounder cannons, named for the weight of cannonball they fired.
He also took one massive 24-pounder nicknamed "Old Sow" that weighed more than 5,000 pounds, plus several high-arching mortar guns weighing one ton each. The total load: 120,000 pounds of artillery, plus 2,300 pounds of bullet lead and 30,000 gunflints.
In a letter to Washington, Knox promised a "noble train of artillery."
The Winter Gauntlet
On Dec. 9, three boats loaded with artillery set sail on Lake George, N.Y., just as it was icing over. Traveling 40 miles down the frozen lake took eight days. Once the artillery reached the southern shore, Knox's men secured the guns to 42 sleds using more than half a mile of rope. Hauling the heaviest guns required eight horses and additional oxen.
The expedition faced brutal conditions. Knox had to cross the Hudson River four times, navigating ice so treacherous he had each sled team leader carry an axe to cut the lines if a cannon broke through, preventing it from dragging horses underwater. One cannon did crash through the ice into the Mohawk River, and another nearly followed into the Hudson.
Exceedingly cold weather, snowstorms and unexpected midwinter thaws compounded the journey. Knox himself nearly froze to death walking through three feet of snow in a blizzard. In one letter to Washington, he wrote simply: "It is not easy to conceive the difficulties we have had."
After reaching Albany on Dec. 26, Knox had to wait for the Hudson ice to thicken sufficiently. His men tried pouring water on existing ice to accelerate the freezing process. The first cannons arrived in Albany by Jan. 4, 1776, but the ice remained treacherous.
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Through the Berkshires
The expedition then faced the Berkshire Mountains. On Jan. 10, Knox wrote that he had "climb'd mountains from which we might almost have seen all the kingdoms of the Earth." The next day, he marveled from Blandford: "It appear'd to be almost a miracle that people with heavy loads should be able to get up & down such hills as are here."
At one particularly steep hill leading to the Connecticut River valley, the lead crew refused to continue without sufficient snow. Knox hired more oxen and convinced them to press on. News of the artillery train spread as it moved east. Crowds came out to watch. In Westfield, Massachusetts, Knox loaded one of the big guns with gunpowder and fired it to cheering crowds.
The expedition passed through Brookfield, Spencer, Leicester, Worcester, Shrewsbury, Northborough, Marlborough, Southborough, Framingham, Wayland, Weston, Waltham and Watertown. John Adams reported seeing the artillery train pass through Framingham on Jan. 25.
On Jan. 27, 1776, Knox's noble train of artillery entered Cambridge.
The British Evacuate
Washington now had the firepower he needed. He placed Knox's cannons at strategic points in Cambridge and Roxbury. On March 4, 1776, under cover of darkness, 2,000 Continental soldiers maneuvered the artillery to Dorchester Heights, overlooking Boston and its harbor.
On March 5, British General William Howe looked up at the fortified heights and exclaimed, "These fellows have done more work in one night than I could make my army do in three months."
Trapped by Knox's artillery with no way to defend against the cannons raining fire on his fleet, Howe gave the order to evacuate on March 6. On March 17, 1776, British forces, accompanied by many Loyalists, sailed from Boston. The Continental Army had won its first major victory.
A Career Launched
Henry Knox was no one-hit wonder. Washington promoted him to chief of artillery for the Continental Army, a position Knox held throughout the war. He planned and executed Washington's audacious Christmas night crossing of the Delaware River in 1776, providing artillery support for the surprise attack at Trenton.
Knox became Washington's most trusted artillery commander and one of his closest friends. He rose to major general, becoming the youngest American to hold that rank in the Continental Army. After the war, Washington appointed Knox as the nation's first Secretary of War, a position he held from 1785 to 1794.
The artillery Knox hauled through winter wilderness didn't just break the siege of Boston. It demonstrated that amateur colonists could match British military logistics through determination and ingenuity. The victory provided a crucial morale boost for the Continental Army and proved the rebellion could succeed.
The Trail Today
The route Knox followed is now known as the Henry Knox Trail. In the 1920s, New York and Massachusetts officials formed a committee to identify the route based on Knox's diary and correspondence. They installed granite markers along the trail, each featuring a bronze tablet with a simplified map and bas-relief image of cannons on sleds pulled by oxen.
The markers read: "Through this place passed General Henry Knox in the winter of 1775-1776 to deliver to General George Washington at Cambridge the Train of Artillery from Fort Ticonderoga used to force the British army to evacuate Boston."
Local historians continue working to trace the exact route. Some portions have become driveways and lawns, while others remain hidden in remote forests. But the feat Knox accomplished -- moving 60 tons of artillery 300 miles through winter wilderness in 40 days -- remains one of the Revolutionary War's most remarkable achievements.
Washington once wrote of Knox: "There is no man in the United States with whom I have been in habits of greater intimacy." That friendship began 250 winters ago, when a young bookseller arrived in Cambridge with the impossible: a noble train of artillery that saved the Revolution.
Sources: Mass Moments (website), "Henry Knox Brings Cannon to Boston." Massachusetts Historical Society, "Henry Knox diary, 20 November 1775-13 January 1776." American Battlefield Trust, "The Guns of Ticonderoga." The Berkshire Edge, "Henry Knox and trekking on the Knox Trail," (2026). The Boston Globe, "Retracing the improbable steps of Henry Knox, guess by educated guess," (2025). Washington Examiner, "On This Day: Col. Henry Knox" (2026).
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