The ingenious solution was to haul the guns into position under cover of darkness during a single night. Noise from the operation would be muffled by firing steady salvos from Roxbury, Cobble Hill, and Lechmere Point and by wrapping wagon wheels with straw to deaden their sound. To obstruct the vision of British troops, the patriots would throw up intervening screens of hay bales. Washington and his generals hit upon the clever expedient of prefabricating the fortifications elsewhere, making it necessary only to transport them to the heights. By now a champion bluffer, Washington also had earth-filled barrels lined up before the parapets, giving a deceptive show of strength. These convenient props could also come thunderously crashing down on any British troops foolhardy enough to storm the hillside.
By late February, Washington was persuaded that the contemplated operation would lure the British into an engagement on terms favorable to the Americans. One lesson he had learned from the French and Indian War was that fear was contagious in battle, especially among inexperienced troops. Without disclosing the exact nature of the impending operation, he warned his soldiers bluntly that “if any man in action shall presume to skulk, hide himself, or retreat from the enemy without the orders of his commanding officer, he will be instantly shot down as an example of cowardice.”16
At midnight on March 2 the patriots began firing diversionary volleys at the British, who replied with earsplitting cannon fire—sounds of war loud enough to startle Abigail Adams from her sleep in nearby Braintree. These cacophonous exchanges persisted through the next night. On the night of March 4, Washington recalled, the moon was “shining in its full luster,” as the weather cooperated with the unfolding operation. “A finer [night] for working could not have been taken out of the whole 365,” wrote the Reverend William Gordon. “It was hazy below [the Heights] so that our people could not be seen, though it was a bright moonlight night above on the hills.”17 Washington directed operations on horseback, his familiar form visible in silhouette to his men. Under the tutelage of Henry Knox, the American artillery strafed Boston in a ferocious cannonade. “Our shells raked the houses and the cries of the poor women and children frequently reached our ears,” wrote Lieutenant Samuel Blachley Webb.18
Hidden by the roar and flash of cannon, General John Thomas supervised three thousand soldiers and oxen-led wagons as they dragged the big guns, weighty barrels, and preassembled ramparts up the steep slope. The unforgiving ground was covered with ice two feet thick, packed hard as rock. At sunrise on March 5 the British saw that something wondrous had happened overnight: Dorchester Heights had been converted into a full-fledged fortress, making the British occupation of Boston seem untenable. Not a single American soldier had been lost in the operation. Legend maintains that, upon beholding the massed American guns, an incredulous General Howe exclaimed, “My God, these fellows have done more work in one night than I could make my army do in three months.”19 On this anniversary of the Boston Massacre, Washington strode among his men, shouting at them to “remember it is the fifth of March, and avenge the death of your brethren,” and the men roared back their assent.20 As in the French and Indian War, Washington was no remote leader but an active, rousing presence. “His Excellency General Washington is present animating and encouraging the soldiers,” wrote Dr. James Thacher, “and they in return manifest their joy, and express a warm desire for the approach of the enemy.”21
The second phase of Washington’s strategy called for Generals Putnam, Sullivan, and Greene to speed across the Charles River with four thousand men and pummel Boston if Howe’s troops could be drawn out into a bloody engagement at Dorchester Heights. The British seemed about to wade into this cleverly laid trap. Despite skepticism among some officers, General Howe elected to throw more than two thousand troops against the heights, and legions of bystanders scurried eagerly across the surrounding hills to await the grand battle scene. Washington was convinced that, if he could flush the British from Boston, they could be bombarded by lethal fire.
John Trumbull remembered Washington making one last meticulous survey of his defenses, only to be frustrated by an unforeseen shift in the weather: “Soon after his visit, the rain, which had already commenced, increased to a violent storm and [a] heavy gale of wind, which deranged all the enemy’s plan of debarkation, driving the ships foul of each other.”22 Girded for battle, Washington was woefully disappointed and told General Lee that the storm was “the most fortunate circumstance for them and unfortunate for us that could have happen[e]d. As we had everything so well prepared for their reception . . . I am confident we should have given a very good account of them.”23 Some chroniclers have interpreted the raging tempest as an accidental blessing that safeguarded American troops set to cross a mile of open water, only to encounter well-entrenched redcoats in Boston. “Had the storm not intervened,” wrote James T. Flexner, “ . . . the troops Washington had intended to land in Boston could never have regained their boats. They would have been trapped. They would either have had to annihilate the British or be themselves entirely defeated.”24 The one certainty is that the storm averted an engagement that might have been decisive for one side or the other.
The upshot of the successful arming of Dorchester Heights was a British decision to evacuate Boston, albeit with British forces largely unmolested. Some historians have argued that Howe planned to leave anyhow and that this fresh threat merely accelerated the timetable and afforded a convenient cover story. For Washington, it marked a triumphant finale. On the night of March 9 Howe unleashed a deafening cannonade against Dorchester Heights, firing seven hundred cannonballs, a move that barely camouflaged frantic movements inside Boston to abandon the town. As Washington monitored developments, the town deteriorated into a scene of tumultuous disorder; British troops pitched disabled cannon and produce barrels into the harbor so they wouldn’t fall into patriot hands. Debris bobbed in the water everywhere or lay heaped upon the shore. Crowds of desperate Loyalists surged onto overloaded ships in a chaotic spectacle. The sense of shock was palpable among these refugees, prompting some to dive to death in the chilly waters. As Washington wrote to his brother Jack, “One or two have done what a great many ought to have done long ago—committed suicide. By all accounts, there never existed a more miserable set of beings than these wretched creatures now are, taught to believe that the power of Great Britain was superior to all opposition.”25 On Sunday, March 17, with the distant din of patriot cheers ringing in their ears, nine thousand quick-stepping redcoats and numerous Loyalists boarded an armada of 120 ships stretching nine miles out to sea and left Boston forever. “Surely it is the Lord’s doings and it is marvelous in our eyes,” wrote Abigail Adams .26
In a measure of Washington’s growing maturity, he indulged in no public bragging, even if he gloated in the privacy of print. Priding himself on staying cool-headed, he didn’t give way to jubilation, especially since it took ten days for the British ships to sail away. One of his hallmarks as a commander was unremitting vigilance, and he worried that British soldiers would slip ashore in disguise or even launch a surprise attack. On the alert for medical problems, Washington made sure that the first five hundred men who entered Boston were immune to smallpox. Instead of basking in the limelight, he permitted General Artemas Ward to lead the victorious vanguard into the city. When Washington himself entered on March 18, he did so unobtrusively, almost invisible to the elated multitudes, and studied the town with professional curiosity. It had suffered extensive damage, with buildings razed, churches gutted, supply depots emptied, and windows smashed, but Washington said the town was “not in so bad a state as I expected to find it.”27 He must have thanked the Lord for the freakish storm, since he found the British defenses “amazingly strong . . . almost impregnable, every avenue fortified.”28 He toured the Beacon Hill home of John Hancock and found the furniture in decent shape, with family oil portraits still on the walls. In their haste to leave, the British had discarded a huge trove of supplies, including 30 cannon, 3,000 blankets, 5,000 bushels of wheat, and 35,000 planks of wood.