The British defeated the French and their Indian allies in the French and Indian War (1754-1763). The result was British control over much of North America. The war had cost England a great deal of money and Parliament decided it was time for the Colonies to pay a share for their own defense.
To raise money, Parliament passed the Stamp Act in 1765. This law required the purchase of tax stamps to buy paper. The Colonists were outraged. After years of "Salutary Neglect" wherein Colonial taxes were not collected by the British, the new policy was unwelcome.
The Colonists had always considered themselves Englishmen. Among the rights granted to all Englishmen was a voice in Parliament -- something they didn't have. With the Stamp Act, "Taxation without representation is tyranny," became a battle cry. Rioting, rhetoric.