In the morning after the Battles of Lexington and Concord, Boston was surrounded by a huge militia army, numbering over 15,000, which had marched from throughout New England. Unlike the Powder Alarm, the rumors of spilled blood were true, and the Revolutionary War had begun. Now under the leadership of General Artemas Ward, who arrived on the 20th and replaced Brigadier General William Heath, they formed a siege line extending from Chelsea, around the peninsulas of Boston and Charlestown, to Roxbury, effectively surrounding Boston on three sides. In the days immediately following, the size of the colonial forces grew, as militias from New Hampshire, Rhode Island, and Connecticut arrived on the scene. The Second Continental Congress adopted these men into the beginnings of the Continental Army. Even now, after open warfare had started, Gage still refused to impose martial law in Boston. He persuaded the town's selectmen to surrender all private weapons in return for promising that any inhabitant could leave town. The siege of Boston was the opening phase of the American Revolutionary War.