It now remained for these regiments to go on fortifying the water-front of this site to keep the ships out of the river, and, in addition, to secure themselves against an attack by land. What Lee's plan was in reference to Columbia Heights has already been seen. Here he proposed to establish a camp with Fort Stirling and the Citadel among its defences, the former of which had been nearly completed and the latter begun by Ward's regiment and the inhabitants. In consequence, however, of a move made by General Putnam soon after his arrival, it had evidently become necessary to enlarge this plan. Governor's Island, just off the edge of which were moored the British men-of-war, had not been occupied by either Lee or Stirling; but it lay within cannon-shot of the Battery and Columbia Heights, and an enemy once lodged there could work us mischief. General Putnam noticed its position, and he had not been here three days before he wrote, April 7th, to the President of Congress: "After getting the works [in New York] in such forwardness as will be prudent to leave, I propose immediately to take possession of Governor's Island, which I think a very important post. Should the enemy arrive here, and get post there, it will not be possible to save the city, nor could we dislodge them without great loss."[32] On the very next night he carried out his proposal, as appears from the following account of the manoeuvre preserved among the papers of Colonel G. Selleck Silliman, of Fairfield, Connecticut, who had recently come down to relieve the troops under Ward and Waterbury: [Footnote 32: _Force_, Fourth Series, vol. v., p. 811.] "_Tuesday Morning, 9th April._--Last Evening Draughts were made from a Number of Regiments here, mine among the Rest, to the Amount of 1,000 Men. With these and a proper Number of Officers Genl Putnam at Candle lighting embarked on Board of a Number of Vessels with a large Number of intrenching Tools and went directly on the Island a little below the City called Nutten [Governor's] Island where they have been intrenching all Night and are now at work, and have got a good Breast Work there raised which will cover them from the fire of the Ships; and it is directly in the Way of the Ship coming up to the Town. The Asia has fallen down out of Gun Shot from this Place and it deprives the Ships of the only Watering Place they have here without going down toward the Hook."[33] There was something of the Bunker Hill flavor about this move, and it was Prescott's Bunker Hill regiment that was first stationed[34] on the Island, which subsequently became one of the strongest posts of the position. At the same time another party occupied Red Hook,[35] on Long Island, which commanded the channel between the Hook and Governor's Island. [Footnote 33: MS. letter from Colonel Silliman to his wife, in possession of Mrs. O.P. Hubbard, New York City.]