Battle of Breed's Hill / Bunker Hill A Brief History After retreating from Lexington in April, 1775, the British Army occupied Boston for several months. Realizing the need to strengthen their position in the face of increasing anti-British sentiment in and around Boston, plans were developed to seize and fortify nearby Dorchester Heights and Charlestown peninsulas. The peninsulas offered a commanding view of the seaport and harbor, and were important to preserving the security of Boston. The Americans caught word of the British plan, and decided to get to the Charlestown peninsula first, fortify it, and present sufficient threat to...