On March 26, 1776, a British fleet of 125 transports and warships left Boston Harbor bound for Halifax, Nova Scotia. Aboard were General William Howe, some 9,000 officers and men, and more than 1,000 Loyalists and their families. For nine months, the British had been unable to venture beyond the city of Boston, which was surrounded by colonial troops. The Continental Army had recently taken Dorchester Heights overlooking the harbor, which they fortified with cannons and mortars captured at Fort Ticonderoga, New York. However, in return for a promise by General Howe that Boston would not be burned, the British fleet left the harbor unmolested. The anniversary of this date is conveniently celebrated by the Irish American (and other) residents of Boston and Suffolk County on March 17.