The American Revolution actually began a long time before the fighting started. It began when Britain needed money after the expensive French Revolution. The parliament decided the easiest way to get the money would be to tax the Americans. The parliament passed four new laws for support of the British troops in America.
The first law or act was the Sugar Act of 1764 which put taxes on products from the French West Indies. The second act was the currency act of 1764 which said colonists could not print money or start their own banks. The third act was the quartering act of 1765 which made colonists pay for shelter and supplies for British troops. The last act was the Stamp act which made Americans purchase and use stamps on newspapers, pamphlets, all legal documents and other things.
King George III realized that the Americans were starting to become to independent so he sent troops to in-force the rules and show them he was in charge. The troops being there increased the Americans bad feelings. This led to the Battle of Lexington and Concord on April 19,1775. At this place the first shot or better known as the shot heard around the world was fired! This officially started the American Revolution