=148. Difficulties confronting Washington.=—Washington soon reached the scene of action, and took command of the American army on July 3, under an elm tree which still stands near Harvard University, in Cambridge, commemorating the event. The difficulties which beset him might well have disheartened a less resolute and skillful commander. His embarrassments were chiefly of three kinds. In the first place, the number of men at his command was at no time greater than the number of the regular British troops confronting him. His force had left their farms in midsummer without having enlisted for any definite period, and when the first burst of enthusiasm died away, it was very difficult to keep the ranks filled. In the second place, each of the provinces had its own laws, and consequently there was no uniformity of method and no subordination to any common authority. Washington dismissed sundry officers for insubordination, and he was obliged persistently to urge the governors of the several states to keep their quotas full.[70] In the third place, he soon discovered that the Americans had very little ammunition. There was not enough for a single battle, and it was plain that if at any time during the fall or winter the British should make a vigorous attack, they would in all probability succeed in breaking up the American army. To supply this deficiency Washington sent messengers in every direction. He dispatched an expedition to seize the British stores at the Bermudas; he had cannon dragged on ox sleds from Ticonderoga; and he gradually collected powder from all the country towns in the region. [Illustration: THE WASHINGTON ELM, CAMBRIDGE.] [Illustration: BOSTON AND ENVIRONS, 1776] =149. The Taking of Dorchester Heights.=—Notwithstanding all these discouragements, Washington drilled the army vigorously throughout the fall and winter. Early in March, 1776, he determined upon a movement which was destined to prove decisive. Dorchester Heights, projecting from the mainland south of Boston, commanded the town from this direction, as Charlestown commanded it from the north. Howe committed a fatal blunder in not establishing himself upon this point; and the consequence was, that one morning he discovered that the enterprising enemy had not only occupied the hill, but had thrown up formidable works commanding the city. A few days later, on March 9, the Americans also constructed works on Nook’s Point, which commanded the Neck and brought every part of the city within range.