The imposition of a Stamp Tax united the colonies for the first time. In June 1765 the Massachusetts assembly circulated a letter to the other colonies calling on them to send representatives to a meeting to be held in New York. In October a Congress convened in New York, that included delegates from nine of the colonies.
The Congress issued a thirteen point resolution opposing the stamp taxes. The fifth resolve was the most fundamental one for it reflected the core of the ongoing dispute, it said: “That the only representatives of the people of these colonies are persons chosen therein, by themselves; and that no taxes ever have been or can be constitutionally imposed on them but by their respective legislatures.”
The Stamp Tax had managed to unify the colonist. While every colony had its own identity, for the first time the colonies had united as one. It was a major step on the road to the Revolution. Full Text of the Stamp Tax Resolutions