The “shot heard ‘round the world” had rung out just weeks earlier when the Massachusetts minutemen turned back the British regulars. As the news spread across the colonies that a first battle had occurred at Lexington and Concord — a minor victory for the minutemen, but a victory nonetheless — volunteers from New England quickly moved toward Boston. Within days, those additional minutemen, armed and prepared for battle, had joined their Patriot brothers in the city and in the outlaying communities.

By early June, the Sons of Liberty learned that additional British troops had been ordered to Boston. Their purpose: to gain control of the harbor and put a stranglehold on the city for its actions against the Crown. Colonel William Prescott immediately responded by organizing 1,200 colonials at the key vantage points of Bunker Hill and Breed’s Hill, with others stretched in a fortified line toward Charlestown.

In the early morning hours of June 16, 1775, the British military realized that colonial forces were manning a line on the Charlestown Peninsula and attacked, assuming an easy victory awaited.

They were mistaken.

The minutemen halted the British advance, inflicting heavy casualties, especially among the officer ranks. A third and final assault proved effective, and the peninsula fell to British control. However, the costly victory was sobering for the British. The leadership corps found it unimaginable that colonial “irregulars” could stand against the Crown. A change in the British plans was made: There would be no more direct frontal attacks, and strategies in other major port cities were quickly altered as the minutemen across the colonies began assembling to repulse the Redcoats. The strength of the newly created Continental Line, under the command of General George Washington, convinced the Crown to supplement British forces with highly trained Hessian troops. These mercenaries for hire had gained significant experience in the recent European wars, though it remained to be seen if their skills would tilt the seesaw in Britain’s favor.

Boston remained the epicenter of conflict. The British controlled the harbor, allowing easy reinforcement of their troops in the city, and the colonials controlled the high points overlooking the harbor area, allowing the effective use of artillery. The Brits under General Thomas Gage and the colonials, led by Artemas Ward, would soon face off in a major and memorable engagement.

On the evening of June 16, Colonel Prescott led his men into positions where the artillery could fire directly into the city. At the same time, work of fortifications began first on Bunker Hill, but then the main effort was transferred to Breed’s Hill, based on the recommendation of colonial engineer Captain Richard Gridley since it was closer and more defensible. Imagine a fort-like structure 130 feet square with ditches, hastily constructed six-foot earthen walls, and a platform where troops could quickly mount, fire, and switch positions. British General Henry Clinton noticed the activity on the hills but was unable to convince Generals Gage and William Howe that they should prepare for a dawn attack.

When a sentry noticed the new fortifications in the early dawn, his commander ordered him to fire. And then a deadly comedy of orders to “fire,” “cease fire,” and then “fire” began. Not until later that morning did General Gage order all 128 guns in the harbor to rain down fire on the batteries along the hills. Unfortunately for the British, the barrage was ineffective since the fortifications were out of the range of the Crown’s guns. Only one colonial soldier was killed.

Both sides began reorganizing their troops and positioning for combat.

The first attack began at 3 p.m. as General Howe led his light infantry troops forward. At the same time, two large guns arrived from Bunker Hill. General Howe’s troops faltered, confused by the waist-high grasses on the hillside, the intense heat (wool uniforms and Boston in June!), and heavy packs not needed for the attack. Orders to advance sounded, and advance the British troops did. The colonials waited until the Redcoats were within 50 paces before firing.

Were they told to “wait until you see the whites of their eyes”? Probably not. But they were told that munitions were in short supply and to exercise certainty when possible. In other words, do not waste your gunpowder until you can fire with accuracy. It was a command that resulted in large British casualties.

The second and third attacks against the colonials were just as disastrous. When the smoke finally cleared from the hillside, the results were obvious and would be verified by a count. The British had 226 dead and 828 wounded — that’s a 40% casualty rate, with 19 key officers dead. The colonials had lost 138 men, and while they technically were losing control of the city, the Battle of Bunker Hill alarmed the members of Parliament. King George III responded with additional harsh measures, and within weeks, Parliament issued the Proclamation of Rebellion, stirring an increasingly patriotic response among the colonists.

If all 13 colonies were not already committed to rebellion, the number of colonists ready to strike for freedom was increasing daily.