Final answer:
The British army made three assaults during the Battle of Bunker Hill, with the third assault being decisive in forcing the American retreat despite heavy British casualties.
Step-by-step explanation:
The British army made three assaults during the Battle of Bunker Hill. Initially, the Americans repelled the first two attacks by the British. Despite organizational issues and being at a disadvantage with ammunition, the American forces proved capable of standing their ground. However, during the third assault, with the Americans running low on ammunition, the British forces were able to overwhelm the American positions. This third attack proved decisive, leading to the British taking control of Breed's Hill and the Charlestown peninsula.
Despite the technical victory for the British in gaining control of the region, it came at a considerable cost. They suffered heavy casualties, which included 226 soldiers killed and over 800 wounded. The battle had an impact beyond the immediate military outcome, affecting British morale and leadership decisions, and boosting the American confidence.