By the 1760s, the 13 colonies were almost 2 million people strong and feeling important. They'd helped the regular British army from back home beat the French and American Indians in the war by the same name that ended in 1763 and now wanted to take over land across the mountains. They were stopped, however, by a declaration of the British Parliament — the Proclamation of 1763 — that closed land west of the Appalachian mountains to settlement. Other restrictions and taxes followed, namely the Stamp Act of 1765, which taxed cards, documents, and even newspapers, and Parliament's taxing tea as a means to regulate prices in order to favor Britain's own investors.
Objecting to lawmaking without Colonial representation, colonists, thinly disguised as American Indians, staged the Boston Tea Party in which they boarded three British ships and dumped 45 tons of tea overboard. They didn't damage the ships, but tea washed up on shore for weeks.
Parliament then passed the Intolerable Acts in 1774 to punish the citizens of Boston by closing down their vital harbor. The British sent over a lot more troops, and the conflict finally erupted at Lexington and Concord, when colonial minutemen responded to what the British called an antiterrorist sweep by shooting up British regulars. Because the fighting had already started, the young and determined Congress had 33-year-old Thomas Jefferson write the Declaration of Independence in 1776. After the battle of Saratoga proved that the backwoods Americans could beat the British army, the French happily piled on to fight their traditional British foes.
George Washington rarely won a major battle, but he stayed in the field for six long years, usually without proper supplies or political support and with a desertion rate of 20 percent per year.
Finally the British decided to take a break from the conflict near the lovely seashore in Yorktown under the protective guns of their mighty navy. Unfortunately for the British, their navy wasn't there, and the French and Americans got the British cornered. Washington finally got the big win he deserved, and it was time for peace and independence.