Despite American protests against the Sugar Act, George Grenville pressed on with his program of compelling the American colonies to pay their fair share of imperial upkeep. The troubles on the frontier sealed the British decision to maintain large forces in America. The colonists, despite the bloodshed launched by Pontiac's conspiracy, saw no need for British forces to remain now that the French were gone. Conditioned by memories of the English civil wars of the seventeenth century and an ingrained distrust of standing armies, they believed that the only purpose for these troops would be to suppress American liberties. The British inflamed these concerns with the Quartering Act of 1765, which required the colonial governments to house and supply these troops. For the Americans this added injury to insult. Colonial legislatures in New York and elsewhere had no stomach for feeding and building barracks for the King's troops. In a tortuous political process, the Americans were gradually pressured into meeting this new obligation. In the meantime, many British soldiers had to find shelter as best they could.

The year 1765 also saw the passage of the Stamp Act. This was an unprecedented direct tax imposed on the American colonists. Grenville believed that he showed great moderation with this legislation. The revenue derived from the Stamp Act would be applied to the defense of America. All the stamp agents would be Americans. The duties would be significantly less than the stamp tax that people in Britain had been paying for decades.

None of this mattered to the increasingly exasperated Americans. This was the British ministry's most flagrant assault yet on the tacit social contract that had governed relations between the mother country and her colonies for more than a century. Unlike the Sugar Act, which struck most directly against American merchants, the regulations of the Stamp Act touched great numbers of average Americans. For the first time, the British government was reaching into the ordinary workings of Americans' lives; most disturbingly, Americans had had no say in this.

Up and down the colonies, the men designated as distributors for the stamps were intimidated into renouncing their office. Only in Georgia were the stamps successfully issued. The most dramatic response to the Stamp Act took place in Boston. A huge crowd of 2,000 angry colonists marched on the home of Andrew Oliver, recently appointed as an agent for the stamps. Oliver was burned in effigy and his house broken into by members of the mob. Thomas Hutchinson, lieutenant governor of Massachusetts, tried to defend Oliver's home; twelve days later another mob attacked Hutchinson's mansion, destroyed it, and scattered the remains of his valuable library on the streets. The mob action against Oliver, which resulted in his speedy resignation, was supported by many of the leading political figures in Massachusetts, including James Otis and the cousins Samuel and John Adams. These men condemned the wanton assault on Hutchinson's home, recognizing that they did not have complete control over the forces that they had unleashed. Benjamin Franklin in Philadelphia, and Henry Laurens, a future president of Congress, in Charleston, had to face down mobs.

America's leaders sometimes had to catch up to their followers. One man who successfully matched the temper of the times was Patrick Henry, a young member of the Virginia House of Burgesses. Introducing a series of resolutions defending the rights of the colonies, he made an impassioned speech that shocked a number of his fellow legislators but delighted many of his countrymen. At its close he declared: “Caesar had his Brutus — Charles the first, his Cromwell — and George the third — may profit by their example…. If this be treason, make the most of it.”

In June 1765 the Massachusetts assembly called for a meeting of delegates from all the colonies to coordinate resistance against the Stamp Act. Delegates from nine colonies met in New York that October. The Stamp Act Congress issued a “Declaration of Rights and Grievances,” principally authored by John Dickinson. The Declaration asserted the loyalty of Americans to the King but reminded Parliament that they possessed all the “inherent rights and privileges” of British subjects. The Declaration condemned the recent attempt to tax Americans, arguing that only the Americans' own legislators could lawfully tax them. Resistance to British taxation was thus a legitimate defense of the American colonists' constitutional rights.