What document was used to protest against the Townshend Acts?

The Massachusetts Circular Letter was instrumental in protesting against the Townshend Acts, which imposed duties on several goods imported to the American colonies. The letter, drafted by Samuel Adams and sent to the colonial assemblies, called for unity among the colonies in their opposition to these acts. It stressed the importance of resistance to what was perceived as an infringement on their rights and liberties by the British government. This coordinated communication among the colonial assemblies helped to galvanize opinion against the taxation without representation that the Townshend Acts exemplified.

Other documents mentioned, such as "Letters from a Farmer in Pennsylvania" and "Common Sense," were important in their own right for articulating colonial grievances and advocating for independence but were not specifically aimed at protesting the Townshend Acts. The Federalist Papers address issues related to the formation of the federal government and the ratification of the Constitution, which are outside the context of the protest against the Townshend Acts. Thus, the Massachusetts Circular Letter is the primary document linked directly to opposition to those specific acts.