April 18, 1775, hundreds of British troops set off from Boston toward Concord, Massachusetts. They reached Lexington the next morning. A shot was fired which is known as "the shot heard around the world" which meant the start of the American Revolution.
Boston was being be surrounded by thousands of American militia. There was a military conflict between the American colonists and the British government during the Revolutionary War.
The Americans secretly moved their troops onto Bunker and Breed's Hill, two unoccupied hills just outside of Boston in Charlestown, Massachusetts after hearing the British planned to take over those hills as tactical advantage.
The next day the British realized what had happened and then the British attacked. Their commander William Howe led three charges up Breed's Hill. The Americans fought back the first two charges, but started to run out of ammunition and had to retreat at the third charge.
Although the British won the battle and gained control of the hills they paid a price. They lost hundreds of soldiers including several officers during the battle. Which gave the Americans the courage and confidence that they could stand up to the British in a battle. Many more colonists joined the army after this battle and the revolution continued to grow in strength.
The American Revolution was a colonial revolt that took place between 1765 and 1783. Many events led up to the victory of the American Patriots and the Thirteen Colonies who won independence from Great Britain to then becoming the United States of America.