The American forces learned that the British were planning on taking over the hills around Boston in order to gain a tactical advantage.As a result of this information, the American secretly moved their troops into Bunker and Breeds hill.They built up fortifications during the night and prepared for battle.The next morning when the British realized what the American had done,they attacked.The American fought back the first two charges but started to run out of ammunition and retreated at the third charge.The British gained the hill ,but their costs were great.Around 226 British were killed and 800 wounded while the American did not suffer nearly as many casualties.