Once again the colonies resorted to boycotts. The Sons of Liberty were reborn to enforce nonimportation, sometimes through violent means. When the new British customs commissioners arrived in Boston in November 1767, they were swarmed by a mob shouting, “Liberty, property, and no commissioners!” In June 1768, some of these commissioners seized the Liberty, a ship owned by John Hancock that was smuggling wine. In response, a crowd attacked three of the commissioners, beating them, sacking their houses, and driving them to Castle William, an island in the harbor, where they were protected by the Royal Navy. The commissioners called for the support of British troops. In due course, four regiments of redcoats were dispatched to Boston.

John Dickinson published one of the most eloquent expositions of the American perspective as a series of articles in the Pennsylvania Chronicle. Styling himself as a simple but level-headed farmer, Dickinson scoffed at the distinction between external and internal taxes. A tax was a tax, and for it to be constitutional it had to be imposed by the representatives of the people. “Those who are taxed without their own consent are slaves,” wrote Dickinson. “We are taxed without our own consent…. We are therefore — SLAVES.” Dickinson's essays found a wide audience on both sides of the Atlantic.

Early in 1768, Samuel Adams persuaded the Massachusetts House of Representatives to approve a Circular Letter to the legislatures of the other colonies. The Circular Letter was a vigorous critique of the Townshend Acts, denying Parliament's authority to tax the colonies, and denouncing the ministry's attempt to make British officials independent of legislative control. When the royal governor of Massachusetts ordered the House of Representatives to rescind the Circular Letter, it refused by a vote of 92 to 17. The governor promptly dissolved the legislature. In the ensuing elections, seven of the legislators who had voted to rescind lost their seats.