But the American Commander-in-Chief had fully anticipated the possible incident of a premature discovery of his design against Dorchester. The success of his plans for the night did not wholly depend upon the undisturbed occupation and fortification of Dorchester Heights. That silent procession of two thousand countrymen was not, as at Bunker Hill, a sort of “forlorn-hope” affair. It was not hurried, nor was it costly of strength or patience. Reliefs came and went; and the system, order, and progress that marked each hour could not have been better realized by day. Instructions had been explicit; and these were executed with coolness and precision, as a simple matter of fact, to be done as ordered by Washington. The silent preparations of the preceding day had provided for the main body of the American army other employment than a listless watch of a vigorous bombardment and its pyrotechnic illumination of the skies. At battery “Number Two,” the floating batteries and batteaux were fully manned, for crossing to Boston. Greene and Sullivan, with four thousand thoroughly rested troops, and these carefully picked men, were ready to move on the instant, if the garrison attempted to interfere with Washington’s original purpose. An eminent historian thus characterized the event: “One unexpended combination, concerted with faultless ability, and suddenly executed, had, in a few hours, made General Howe’s position at Boston untenable.” As soon as General Howe appreciated the changed conditions of his relations to the besieging rebels, he despatched Earl Percy, who had met rebels twice before, with twenty-four hundred troops to dislodge the enemy from Dorchester Heights. The command moved promptly, by boats, to Castle Island, for the purpose of making a night attack. Sharp-shooting, by the American “Minute Men,” in broad daylight, behind breastworks, was not courted by Percy on this occasion, nor desired by General Howe. During the afternoon a storm arose from the south, which increased to a gale, followed at night by torrents of rain. Some boats were cast ashore, and the entire expedition was abandoned. By the tenth of March, the Americans had fortified Nook’s Hill; and this drove the British from Boston Neck. During that single night, eight hundred shot and shell were thrown into the city from the American lines. On the seventeenth of March, the British forces, numbering, with the seamen of the fleet, not quite eleven thousand men, embarked in one hundred and twenty transports for Halifax. The conditions of this embarkation without hindrance from the American army had been settled by an agreement on the part of the British authorities that the city should be left intact from fire, or other injury, and that the property of royalists, of whom nearly fifteen hundred accompanied the troops, should be also safe from violation by the incoming garrison. As the last boats left, General Ward occupied the city with a garrison of five thousand troops.