While Congress gathered and deliberated, the Massachusetts Provincial Congress controlled the army, penning Gage in Boston. The Provincial Congress put Artemas Ward, a veteran of the French and Indian War, in charge of these forces. It called for and received help from the neighboring New England colonies. The army was in perpetual motion as its constituent bands of militia came and went. The men lacked the artillery necessary for a proper siege. Powder and shot were in short supply.

Shiploads of British troops began to arrive in Boston. By the middle of June, Gage had 6,500 men. Among the reinforcements was a trio of British generals destined to play important parts in the war — William Howe, Henry Clinton, and John Burgoyne. These men urged Gage to carve out what Burgoyne called “elbow room” for British forces. The British started planning the occupation of the Dorchester Heights, which dominated the ground south of Boston. Word of this leaked to the Americans, and a council of war decided to counter this by fortifying Bunker Hill on the Charlestown peninsula above Boston. On the evening of June 16, 1,200 Americans crossed the narrow neck of land connecting Charlestown to the mainland and began the construction of a redoubt on Breed's Hill, a position closer to Boston but more vulnerable to attack.

At first light on June 17, the British were shocked to see a large force of Americans building fortifications that overlooked Boston Harbor. Warships immediately began bombarding the Americans. Gage collected 2,200 men to drive the Americans away, entrusting command to William Howe. Given their control of the sea, the British could have landed on the neck of the peninsula and cut off the Americans at Breed's Hill. But worries about American counterattacks from the mainland persuaded Howe to attack from the front. He did plan to flank the Americans by sending a party of troops behind the redoubt along the beach, but a supplementary trench dug by the Americans foiled this maneuver. That afternoon, the British advanced directly up Breed's Hill in two long lines.

Colonel William Prescott and 1,600 militiamen waited for them. According to legend, Prescott told his men, “Don't fire until you see the whites of their eyes.” Whatever Prescott said, his men waited until the redcoats were 150 feet away before opening fire. The effect was devastating. Men fell in heaps. Every officer on Howe's staff was shot down.

The British fell back down the hill. General Howe, who had been in the thick of the fight, personally rallied his men. The British marched back up the hill. This time the Americans waited until the red line was only 100 feet away. Then devastating volleys ripped into the oncoming British. To the farmers on the hill, the effect was of a scythe mowing grass.

Once again, the British gave way. Some companies were reduced to fewer than ten men. Gage sent 400 reinforcements, and Howe organized another attack. He was determined to rout the Americans and ignored the objections of his officers, who asserted that it was murder to ascend the hill again. The British moved forward for the third time, bayonets fixed. Once again, the Americans' volleys ripped into the British, inflicting many casualties. Major John Pitcairn died at the head of his men. But then the shooting stopped; the Americans had run out of powder. The British surged forward, carrying the American entrenchments at the point of the bayonet. Here the Americans suffered most of their casualties. The Americans managed an orderly retreat, and the British were too exhausted to make a vigorous pursuit.

Howe had won a grisly victory. Nearly 40 percent of his command, 1,054 men, became casualties. Of those, 226 were dead. The Americans lost 140 dead, 271 wounded, and thirty captured. After this strategically pointless bloodletting, both sides dug fortifications and were quiet.

George Washington arrived to take command of the Continental army on July 3. What he found was more an undisciplined mass of men than an army. As a veteran who had served with regulars, he was appalled. He was especially disturbed by the easygoing attitudes of the officers; most of those in the militia had been elected by their men and were more politicians than soldiers. In one case he was shocked to find a captain, by trade a barber, shaving his men. Washington immediately began to create greater distance between officers and men. He moved to impose the rules and regulations recently voted by Congress.

Perhaps the most serious problem that faced Washington was the fact that most of his men were militia, serving for short terms of enlistment. They came and went on their own schedule. Most of his army would disappear at the end of the year. Congress authorized the recruitment of regiments to serve for a year. Few men signed up because shorter-term service with friends and family in the militia was more appealing. The problem of keeping men in the army would bedevil Washington for the duration of the war. Early on he wrote, “I have often thought how much happier I would have been if, instead of accepting a command under such circumstances, I had taken up a musket on my shoulder and entered the ranks, or, if I could have justified the measure to posterity and my own conscience, had retired to the back country and lived in a Wigwam.”