The British troops, "greatly exhausted and fatigued and having expended almost all of their ammunition," began to run rather than retreat in order. The officers vainly attempted to stop their flight. "They were driven before the Americans like sheep." At last, about two in the afternoon, after they had hurried through the middle of the town, about a mile below the field of the morning's bloodshed, the officers made their way to the front and by menaces of death began to form them under a very heavy fire. At that moment Lord Percy came in sight with the first brigade, consisting of Welsh Fusiliers, the Fourth, the Forty-seventh and the Thirty-eighth Regiments, in all about twelve hundred men, with two field pieces. Insolent, as usual, they marched out of Boston to the tune of Yankee Doodle, but they grew alarmed at finding every house on the road deserted. While the cannon kept the Americans at bay, Percy formed his detachment into a square, enclosing the fugitives, who lay down for rest on the ground, "their tongues hanging out of their mouths like those of dogs after a chase." After the juncture of the fugitives with Percy, the troops under his command amounted to fully two-thirds of the British Army in Boston, and yet they must fly before the Americans speedily and fleetly, or be overwhelmed. Two wagons, sent out to them with supplies, were waylaid and captured by Payson, the minister of Chelsea. From far and wide Minute Men were gathering. The men of Dedham, even the old men, received their minister's blessing and went forth, in such numbers that scarce one male between sixteen and seventy was left at home. That morning William Prescott mustered his regiment, and though Pepperell was so remote that he could not be in season for the pursuit, he hastened down with five companies of guards. Before noon a messenger rode at full speed into Worcester, crying: "To arms!" A fresh horse was brought and the tidings went on, while the Minute Men of that town, after joining hurriedly on the common in a fervent prayer from their minister, kept on the march till they reached Cambridge. Aware of his perilous position, Percy, resting but half an hour, renewed his retreat.