Final answer:
The Stamp Act of 1765 imposed a direct internal tax on the colonies for printed materials which united the colonists in opposition to Britain, laying groundwork for the American Revolution. It was repealed due to the colonial protest
Step-by-step explanation:
The act that is credited for uniting the thirteen colonies against the British government in 1756 by requiring all legal documents, licenses, and other official papers to have a tax stamp was the Stamp Act of 1765. This act imposed a direct tax on the colonists, significant in that it was not an external tax to regulate trade but rather an internal tax meant to raise revenue for Britain.
The colonists strongly opposed the Stamp Act because it was enacted without their consent, leading to the rallying cry of "no taxation without representation". The widespread opposition united the colonies and set the stage for future acts of rebellion leading to the American Revolution. The Stamp Act was eventually repealed due to the intense pushback from the colonists.