Final answer:
The colonists forced the repeal of the Stamp Act through organization and united action, such as the Stamp Act Congress's declaration, and by imposing economic pressure via boycotts of British goods. This pressure, coupled with advocacy from British merchants, prompted Parliament to repeal the act in 1766.
Step-by-step explanation:
The colonists were able to force the British Parliament to repeal the Stamp Act through a combination of political actions and economic pressure. In response to the Act, the Massachusetts Assembly sent letters to other colonies, leading to the formation of the Stamp Act Congress, which declared taxation without representation unconstitutional. The resulting document, the Declaration of Rights and Grievances, outlined colonial discontent.
More significant perhaps were the widespread boycotts of British goods by the colonists, including a refusal to purchase tea and cloth, which hit British merchants economically. This economic pressure was so impactful that British merchants called on Parliament to repeal the act to safeguard their own interests. Ultimately, Parliament, influenced by this economic pressure and its internal members, repealed the Stamp Act in February 1766.
However, the dynamic of colonial resistance and British legislative action continued to evolve, as the repeal was accompanied by the Declaratory Act, affirming Parliament's authority over the colonies. This action foreshadowed the eventual move toward American independence as tensions persisted.