Final answer:
The slogan "no taxation without representation" was used by Americans to protest the Stamp Act.
Step-by-step explanation:
The slogan "no taxation without representation" was first used by Americans to protest Britain's attempts to raise revenue through the Stamp Act. The Stamp Act, enacted in 1765, imposed various taxes on Americans without their consent or representation in the British government. This slogan became a rallying cry for American colonists who believed that being taxed without having a voice in the decision-making process was unfair and unjust.
Learn more about American protests against the Stamp Act