The basic cause of the growth of conflict was the tension between the British need for revenues and the American desire for autonomy.
Before the French and Indian War, the American colonies had been left more or less to themselves. During this time, they got used to having relative autonomy and came to see it as a right. At the same time, the colonies were growing in population and economic strength and becoming less dependent on the "mother country."
After the French and Indian War, the British needed funds to pay for the war and other costs of empire. They felt the Americans should help to pay so they imposed taxes and tried to increase British control of the colonies to ensure the smooth flow of revenues. This need came into conflict with the expectations the colonists had built up over the years.