3 great reasons would be:
1) The American people were strongly independent. They wanted to do things for themselves. Great Britain was a long way away. The American people didn't want people an ocean away telling them how to live their lives.
2) The British government decided to make the American colonies pay a large share of the war debt from the French and Indian War.
3) Through the Sugar Act, Stamp Act, and other taxes, the British tried to collect taxes that the American people considered harsh.
