The day was boiling hot and the soldiers carried heavy packs with food for three days, for they intended to camp on Bunker Hill.
Straight up Breed's Hill they marched wading through long grass sometimes to their knees and throwing down the fences on the hillside.
The British knew that raw troops were likely to scatter their fire on a foe still out of range and they counted on a rapid bayonet charge against men helpless with empty rifles.

This expectation was disappointed.

The Americans had in front of them a barricade and Israel Putnam was there, threatening dire things to any one who should fire before he could see the whites of the eyes of the advancing soldiery.

As the British came on there was a terrific discharge of musketry at twenty yards, repeated again and again as they either halted or drew back.
The slaughter was terrible.

British officers hardened in war declared long afterward that they had never seen carnage like that of this fight.
The American riflemen had been told to aim especially at the British officers, easily known by their uniforms, and one rifleman is said to have shot twenty officers before he was himself killed.