We sometimes forget that the American revolutionaries were British colonists. They initially tended to see England as the height of culture and as a model government. In 1754–63, they had fought side-by-side with their brothers from the homeland in the French and Indian War. In order to become Americans, they had to first become disgruntled and rebellious and then to carry out a revolution. So we might ask what got them disgruntled.
To begin with, the colonists were Britons of a certain type. More individualistic and rugged personalities were likely to venture across the Atlantic. Some were down and out and had little to lose. Owing to the great distance from England, the colonists also worried about their status as British subjects. For this reason, they felt particularly defensive about their political rights. The British, meanwhile, sometimes showed arrogance and condescension toward the colonists, whom they tended to regard as somewhat primitive and uncouth. Many of those who came to North America were religious minorities and wanted to be left alone. There were the Puritans in Massachusetts, Quakers in Pennsylvania, and Catholics in Maryland.
After time passed, British colonists became distinct from the people in the homeland. Many of them had no accurate sense of what it meant to be an English subject living in England. In turn, the British government did not always grasp the colonial mentality. Landholding and voting rights went hand in hand, so there were broader voting rights in the colonies, where a much higher percentage of people owned land. For this reason, they were more politically entitled. Politics were more localized politics and more personal. Until the mid-1760s, the British government adopted a hands-off policy toward the colonies. By the 1760s, all colonial administrations could essentially govern themselves. The legislatures were filled with politically experienced and articulate individuals. All of this is not to say that the colonists were fully united. The colonies were diverse and had been founded for different reasons: there was no reason they had to band together. Before the mid-1760s, they had shown little sign of unity or concerted action.
The Stamp Act Crisis, broadly defined, created common cause between the thirteen colonies. The British government had spent a lot of money on the French and Indian War, which led to a budgetary crisis in 1764. Prime Minister George Grenville’s government introduced new taxes, both in England and in the colonies. Since the government was supporting a standing army of ten thousand men for the protection of the colonists, it made some sense that the colonists should help defray the cost. Along with the new taxes, the government became more interventionist in the economy and targeted smugglers and lawbreakers. The period of salutary neglect had come to an end. People who had been caught breaking trade laws had to travel to Nova Scotia for trial with no jury. Duties were attached to a number of goods. These policies were unpopular and the colonists' insecurities began to come to the surface. The standing army came to be seen as more of an instrument of control rather than defense.
In 1865, the Stamp Act proper, which proposed that only stamped expensive paper could be used for paper products, was the first tax to be levied directly on the colonies. This proposed act alienated the most educated, articulate, and influential of the colonists, namely lawyers, merchants, and politicians. Since it was to be implemented in all the colonies, it also gave the colonies common cause. At this stage, attacks on British officials and open protest began, with the likes of the Sons of Liberty. The colonial revolutionary mentality had begun to take shape. This trajectory of the colonial mentality is very ably presented in an accessible way, and in much more detail, by Yale University professor Joanne Freeman. See the link below.