Bunker Hill: The Geography and Cost of an Early Clash

In June 1775, the American Revolutionary War was only two months old. British troops occupied the port of Boston, while thousands of colonial militia surrounded the city to prevent them from moving inland. When colonial leaders learned that the British intended to seize the unoccupied high ground of the Charlestown Peninsula across Boston Harbor, they decided to act first. On the night of June 16, colonial forces marched onto the peninsula under the cover of darkness. Their assignment was to build a fortification on Bunker Hill, the tallest elevation in the area. Instead, for reasons historians still debate, the commanders chose Breed's Hill, a lower rise situated closer to the harbor and within range of British naval guns.

Working quietly throughout the night with picks and shovels, the colonists constructed an earthen fort called a redoubt. By dawn on June 17, British sentries in the harbor were stunned to see a six-foot earthen wall commanding Breed's Hill. British commanders quickly realized that leaving colonial forces on this high ground threatened their control of Boston. General Thomas Gage and Major General William Howe decided to launch a direct daylight assault across the water to dislodge the colonial militia.