Answer: They believed there should be no taxation without representation
Explanation: The Stamp Act was one of the reasons for the colonists protest, which, along with other justifiable reasons, consequently led to the American Revolution. The Stamp Act was introduced in 1765 by the British Parliament, directly imposing a tax on the colonies, because it ordered that all printed materials in the colonies must be printed on paper produced in London. Such paper produced in London had an embossed revenue stamp and had to be used for all printed matter, starting from official legal documents to newspapers. In addition, the paper had to be paid for in British currency, not colonial money. The Stamp Act was nothing more than imposing new taxes, because Britain wanted to reduce its debt after the French-Indian War.
As the colonists did not have their representatives in the British Parliament who made all decisions about the colonies and their fates without the colonists, they reasonably felt that the tax should not be without the colonists' representatives in the British Parliament.