During the winter of 1774–75, Americans pressed on with boycotts. Optimists hoped to effect a repeal of the Coercive Acts; pessimists stockpiled arms and ammunition. In Massachusetts, militia units known as minutemen prepared to respond at a minute's notice to any threat from the British troops in Boston.

Thomas Gage realized how desperate the British position was. The people, Gage wrote Lord North, were “numerous, worked up to a fury, and not a Boston rabble but the freeholders and farmers of the country.” Gage requested twenty thousand reinforcements. He also strongly advised repeal of the Coercive Acts, but leaders in Britain could not admit failure. Instead, in mid-April 1775, they ordered Gage to arrest the troublemakers.

Gage quickly planned a surprise attack on a suspected ammunition storage site at Concord, a village eighteen miles west of Boston (Map 6.3). Near midnight on April 18, British soldiers moved west across the Charles River. Paul Revere and William Dawes raced ahead to alert the minutemen. When the British soldiers got to Lexington, five miles east of Concord, they were met by some seventy armed men. The British commander barked out, “Lay down your arms, you damned rebels, and disperse.” The militiamen hesitated and began to comply, but then someone — nobody knows who — fired. Within two minutes, eight Americans were dead and ten were wounded.

The British units continued their march to Concord, any pretense of surprise gone. Three companies of minutemen nervously occupied the town center but offered no challenge to the British as they searched in vain for the ammunition. Finally, at Old North Bridge in Concord, British troops and minutemen exchanged shots, killing two Americans and three British soldiers. As the British returned to Boston, militia units ambushed them, bringing the bloodiest fighting of the day. In the end, 273 British soldiers were wounded or dead; the toll for the Americans stood at about 95. It was April 19, 1775, and the war had begun.