In the early winter of 1775, a young man approached General George Washington at his headquarters in Cambridge with a bold proposal.

Twenty-five-year-old Henry Knox had met the general shortly after the Battle of Bunker Hill, when Washington arrived to take charge of the colonial forces. Knox impressed Washington with his energy, ingenuity, determination, and knowledge of artillery. Now, as winter deepened, Washington faced a predicament. His ragtag troops had Boston under siege, and they occupied high ground from which they could shell the British. But the Americans needed big guns, and Henry Knox had an idea about where to get them.

In May 1775 when Ethan Allen's Green Mountain Boys forced the British to surrender Fort Ticonderoga, they had captured 59 pieces of artillery. Henry Knox proposed traveling 300 miles to Ticonderoga to bring the artillery back to Boston. With enough cannon positioned on Dorchester Heights, the Continental Army stood a good chance of dislodging the British from Boston and scoring a badly needed victory.

Many of Washington's advisors thought the plan was hopeless. The guns would have to be dismantled and loaded onto barges, transported down Lake George before the great 30-mile-long lake froze, then hauled the rest of the way by sledge and oxen over rough trails. Knox would need good luck and better weather — warm days for crossing the lake; cold, snowy nights for the sleds.

The operation involved mobilizing a large corps of men, assembling a flotilla of flat-bottomed boats for the lake trip, building 40 special sleds, and gathering 80 yoke of oxen to pull the 5400-pound sleds. Knox was persuasive; if the mission succeeded, the advantage gained would be spectacular. Washington agreed to the idea, and on December 1^st, the Boston bookseller set off on horseback for Ticonderoga.

He arrived at Ticonderoga four days later. He immediately set about disassembling the guns — 43 heavy brass and iron cannon, six cohorns, eight mortars, and two howitzers. His men removed the guns from their mountings and transported them by boat and ox cart to the head of Lake George. By December 9^th, all 59 guns were loaded onto flat-bottomed boats and headed down the lake.

Until that point, the weather had remained mild, but now the wind picked up and forced Knox's freezing men to row into an icy gale. With heroic effort, they succeeded in getting the last of the cannon to the southern end of the lake just as it began to freeze over.

The next challenge was to move the cannon overland. From Fort George on December 12^th, Knox wrote asking a local farmer to "purchase or get made immediately 40 good strong sleds that will each be able to carry a long cannon clear from dragging on the ground and which will weigh 5400 pound each and likewise that you would procure oxen or horse as you shall judge most proper to drag them. . . . The sleds . . . are to go to camp near Boston."

In less than a week, the determined Knox had acquired the sleds he needed and loaded the cannon. On December 17^th, he wrote to Washington, "I have had made forty two exceedingly strong sleds & have provided eighty yoke of oxen to drag them as far as Springfield where I shall get fresh cattle to carry them to camp. . . . I hope in 16 or 17 days to be able to present your Excellency a noble train of artillery."

Knox was ready, but he could not move. The ground was bare. A good base of snow was needed for the oxen to drag the heavy sleds. Finally, on Christmas morning, Knox awakened to several feet of fresh snow. It was too much of a good thing, since it was difficult to cut a new path through such deep snow. Still, Knox and his men pushed on toward Boston.

By January 5^th, the artillery had reached Albany, but once again, nature did not cooperate. The ice on the Hudson was not deep enough to support the weight of the sleds. During each of the first two attempts at crossing, Knox saw a precious cannon lost to the river. But by the evening of January 8^th, he was able to write in his diary, "Went on the ice about 8 O'clock in the morning & proceeded so carefully that before night we got over 23 sleds & were so lucky as to get the Cannon out of the River, owing to the assistance the good people of the City of Albany gave."

Continuing eastward, Knox and his men crossed the border into Massachusetts and struggled on to Springfield. From here both the roads and the weather improved. With 80 yoke of fresh oxen, the expedition passed through Brookfield, Spencer, Leicester, Worcester, Shrewsbury, Northborough, Marlborough, Southborough, Framingham, Wayland, Weston, Waltham, and Watertown. On January 24, 1776, Knox's "noble train of artillery" entered Cambridge.

Six weeks later, on the night of March 4^th, Washington's gun batteries in Cambridge distracted British troops while several thousand Americans quietly maneuvered the artillery up Dorchester Heights and frantically constructed emplacements. Logs painted to look like cannon made it seem as if they had even more firepower than they did.

The next morning an astonished British General Howe looked up at Dorchester Heights and remarked, "The rebels did more in one night than my whole army would have done in one month." Thanks largely to Henry Knox, the vaunted British Army had little chance of ending the siege of Boston. On March 17^th, British troops and Tory sympathizers began the evacuation of Boston.