When and where did fighting between Americans and the British empire begin?

After more than a decade of political and economic tensions between the American colonies and the British Empire, fighting broke out in April 1775. British soldiers learned that Americans were stockpiling weapons and ammunition in the towns of Lexington and Concord, west of Boston, Massachusetts. When British troops marched to Concord to seize these weapons, they were met by an angry group of Minutemen, who began firing on the British. The British fled back to Boston with the colonists in pursuit. By the time they arrived in Boston, they had suffered 73 men killed and 174 wounded -- sizable casualties for an eighteenth-century battle.

Once the fighting had begun, American colonists led by Benedict Arnold and Ethan Allen quickly seized the British fort at Ticonderoga, New York. It took them weeks to haul the cannon they captured there to Boston. With these cannon placed on hills above Boston, the rebels drove the British out of the city; the British moved their headquarters south to New York City. In June 1775, Americans inflicted some of the war's largest casualties on the British in the Battle of Bunker Hill. (This famous battle was misnamed; it was actually fought on Breed's Hill.)

In response the outbreak of fighting, the Continental Congress began raising an army. It also wrote the Olive Branch Petition to King George III of Britain in a last-ditch effort to avoid war. Even after the Battle of Lexington and Concord, Americans were still unsure whether they wanted war or peace.