Somerville) in colonial times by a short, narrow isthmus known as the Charlestown Neck. It is best known as the location where in 1775, early in the American Revolutionary War, most of the fighting in the Battle of Bunker Hill took place. In the 19th and early 20th centuries the peninsula's shape and connections to other landforms were significantly altered, with the waters of the Charles River between Cambridge and Charlestown heavily filled in. Much of the hill is now occupied by residential construction, but the summit area is the location of the Bunker Hill Monument and other memorials commemorating the battle. The hill is about high, and is topped by Monument Square, site of the Bunker Hill Monument. The hill slopes fairly steeply to the east and west. In addition to its historic sites and tourist-oriented facilities, the hill is the site of a great deal of residential property, as well as supporting municipal and retail infrastructure. It is about from Bunker Hill. History The Americans, having caught word of a British plan to fortify the Charlestown peninsula, decided to get to the peninsula first, fortify it, and present sufficient threat to cause the British to leave Boston. On June 16, 1775, under the leadership of General Putnam and Colonel Prescott, the Americans stole out onto the Charlestown Peninsula with instructions to establish defensive positions on the hills overlooking Boston. A redoubt, a small and usually temporary defensive fortification, was constructed on nearby Breed's Hill, probably due to its closer proximity to Boston compared to Bunker Hill. The next morning, June 17, the British were astonished to see the rebel fortifications upon the hill and set out to reclaim the peninsula. The resulting conflict was called the Battle of Bunker Hill because that is where Prescott originally intended—and was ordered—to build the fortifications. Also, some people considered Breed's Hill a part of Bunker Hill, while others called it Charlestown Hill. British soldiers under Howe sent 2,400 men to attack Breed's Hill. A force of 1,500 colonists held off two British Army attacks, but the third attack, by British Royal Marines, forced the rebels to retreat. 450 colonists were killed or wounded, compared to 1,150 British casualties. In 1825, the Bunker Hill Monument Association began construction of the Bunker Hill Monument, acquiring of land for the purpose. Construction William Ticknor, a well-known Boston lawyer and antiquarian, first suggested the memorial.