Who initiated a call for action against the Stamp Act in Massachusetts?

James Otis was the one who initiated a call for action against the Stamp Act in Massachusetts. In 1764, Otis publicly took a stand against the British taxation policies, particularly emphasizing the illegitimacy of taxation without representation. His arguments laid the groundwork for organized resistance to the Stamp Act that followed in 1765, and he was pivotal in articulating the colonists' grievances. Otis' influential pamphlet, "The Rights of the British Colonies Asserted and Proved," called for unity among the colonial assemblies to resist British oppression, thus igniting broader political action in the colonies against the Stamp Act.

The Stamp Act itself generated significant unrest, ultimately leading to the formation of groups like the Sons of Liberty and unifying many colonists against British authority. His early activism is credited with galvanizing support among colonists and influencing other leaders, which played a crucial role in shaping the American Revolutionary movement.