For about 150 years - until 1764 - the colonists tolerated British rule. But when the King and Parliament began to enforce trade laws and imposed taxes on sugar (to help Britain pay for the debt caused by the French and Indian War), Americans grew increasingly upset. The Sugar Act also prohibited Americans from importing foreign rum and French wines. That made matters worse.
People - like James Otis - raised the issue of taxation without representation. Why should American colonists pay taxes to England when they had no representation in the English Parliament?
But England was just getting started with colonial taxes. By the following year, Parliament (for the first time) imposed a tax (the Stamp Act) which required Americans to pay duties directly to England, not to local legislatures. The law required Americans to buy stamps for ALL printed material (including playing cards, newspapers, dice, and legal documents), thus taxing the most mundane aspects of daily life. The people were outraged. To make matters worse, George III expected "his" colonists to house and feed British soldiers (the Quartering Act of 1765).
The colonists elected representatives to formally discuss these developments. The "Stamp Act Congress" sent a petition to George III and Parliament requesting a repeal of the tax and reminding the King that taxation without representation violated basic civil rights. Meanwhile, daily business and legal transactions nearly stopped when the people refused to buy the stamps.
Conceding the point on the Stamp Act, Parliament and the King repealed it in March of 1766, but replaced the law with something much more onerous. The Declaratory Act gave the British government exclusive power to enact any and all laws governing the colonies.
By 1767, the Townshend Revenue Acts levied a new tax - this time on imports like tea, paper, glass, lead and paints. To make sure the duties were paid, the King sent British custom officials to Boston - where they were tarred and feathered.
The stage was set for violence.