Early Campaigns, 177576
Congress in September, 1775, authorized direct enlistments in the Continental Army for one year, instead of depending completely on the separate colonies for regiments recruited for shorter periods. This was intended to provide Washington with an army of 20,000 men, paid and supplied by the Continental Congress. However, he had only 9,000 of the Continental Line, supplemented by 5,000 militiamen, when he moved against Boston in March, 1776.
With cannon brought from Fort Ticonderoga during the winter, Washington's troops occupied Dorchester Heights, which commanded the city. General Howe, who had succeeded Gage, felt unable to attack another fortified height, so he abandoned Boston and sailed with his troops for Halifax, Nova Scotia.
While Washington was preparing to liberate Boston, British ships attacked southern coastal cities. Early in 1776, a joint British military and naval expedition was organized to capture Charleston, South Carolina, as a base for conquering Virginia and the Carolinas. British sympathizers in the area were counted upon to help. However, these loyalists were put down by patriot militiamen. When British troops under General Clinton attempted to land at Charleston, they were met with such heavy fire that the expedition was abandoned.
In the winter of 177576 an effort to capture Canada was made by American forces under General Richard Montgomery and Colonel Benedict Arnold. Montreal was taken temporarily, but Montgomery was killed and the Americans were defeated at the city of Quebec. Washington then correctly expected the British to attack New York by way of Canada or the Atlantic coast, or both. He moved his army from Boston to New York City.
Arnold, meanwhile, withdrew to Lake Champlain to block the British there. He built a fleet of lake vessels that held the lake until October, 1776, when he was defeated at the Battle of Valcour Island. By then it was too late in the year for the British to continue their invasion.