Americans Occupy Dorchester Heights
With artillery brought from Fort Ticonderoga, George Washington was ready to make a surprise move that would force the British army out of Boston. The plan was to take possession of some hills south of Boston, build fortifications, and bring in artillery — all in a single night. If they did it carefully and quietly enough, the British wouldn’t notice the fortifications until the next morning, and the Americans would be in a perfect position: close enough to easily bombard the town, but safe within their fortifications.
The ground was still frozen, and digging would be difficult, so they made big wooden frames called “chandeliers” which could be hauled in by wagon, assembled on the spot, and stuffed with hay bales and fascines (bundles of brushwood). These would serve as fortifications until they could dig in more permanently. An artillery bombardment would cover their noise and keep the enemy from noticing until it was too late.
The operation got underway after dark on March 4, 1776. Dr. James Thacher, a surgeon in the American army, described the scene:
We are favored with a full bright moon, and the night is remarkably mild and pleasant; the preparations are immense; more than three hundred loaded carts are in motion. By the great exertions of General Mifflin, our Quarter Master General, the requisite number of teams has been procured. The covering party of eight hundred men advance in front. Then follow the carts with the entrenching tools; after which, the working party of twelve hundred, commanded by General Thomas, of Kingston. Next in the martial procession are a train of carts, loaded with fascines and hay, screwed into large bundles of seven or eight hundred weight. The whole procession moved on in solemn silence, and with perfect order and regularity; while the continued roar of cannon serves to engage the attention and divert the enemy from the main object.
The men worked quickly and quietly, and when morning came, the British had an unpleasant shock. One British officer wrote:
March 5. — This is, I believe, likely to prove as important a day to the British Empire as any in our annals. We underwent last night a very severe cannonade, which damaged a number of houses, and killed some men. This morning, at daybreak, we discovered two redoubts on the hills on Dorchester-Point, and two smaller works on their flanks. They were all raised during the night, with an expedition [i.e. speed] equal to that of the Genii belonging to Aladin’s wonderful lamp. From these hills they command the whole town, so that we must drive them from their post, or desert the place. The former is determined upon, and five regiments are already embarked…
But a storm “more violent than anything I ever heard” kept the British from attacking that night; and by the next day, the Americans were so well fortified that there was no hope of dislodging them. General William Howe, the British commander-in-chief, decided to evacuate as soon as possible, taking with them any Loyalist Americans who wanted to go. A Boston merchant named John Rowe described the general confusion in town:
They are making the utmost Speed to get away & carrying Ammunition, Cannon & everything they can away, taking all things they meet with, never asking who is Owner or whose Property — making havock in every house & Destruction of all kinds of Furniture.
Sources
A Military Journal During the American Revolutionary War (by James Thacher), p. 88.
American Archives, 4th Series, 5:425-26.
Letters and Diary of John Rowe, Boston Merchant, p. 302.