So, on the evening of June 16, 1775, there was a stir of preparation in the American camp at Cambridge, and late at night the men fell in near Harvard College.
Across the Charles River north from Boston, on a peninsula, lay the village of Charlestown, and rising behind it was Breed's Hill, about seventy-four feet high, extending northeastward to the higher elevation of Bunker Hill.

The peninsula could be reached from Cambridge only by a narrow neck of land easily swept by British floating batteries lying off the shore.

In the dark the American force of twelve hundred men under Colonel Prescott marched to this neck of land and then advanced half a mile southward to Breed's Hill.

Prescott was an old campaigner of the Seven Years' War; he had six cannon, and his troops were commanded by experienced officers.

Israel Putnam was skillful in irregular frontier fighting, and Nathanael Greene, destined to prove himself the best man in the American army next to Washington himself, could furnish sage military counsel derived from much thought and reading.
Thus it happened that on the morning of the 17th of June General Gage in Boston awoke to a surprise.