The colonists' grievances were pretty clearly defined in some of their statements. Stemming largely from taxation, the colonists' believed they were being taken advantage of—and truthfully, they were. Great Britain was fighting more and more wars, including the French and Indian War that took place on the American continent. This drained their resources, and so, instead of going into the purse of Parliament or taking from the citizens living in the British Isles, they levied taxes and fines against the colonists.

Unfortunately, the colonists had little say in these fines and had absolutely no representation in the government to fight against these taxes. The most frustrating thing was that the colonists were being taxed to pay for wars and events that they perceived as having nothing to do with them, which they had no opportunity to fight—leading to the cry "No taxation without representation."

Additionally, during and after the war, the British were forcing colonists to quarter soldiers within their houses. They gave up land and house space to soldiers who were doing little to protect the interests of the colonies and, at this time, were mainly there to enforce collection of taxes. All of these issues boiled to a head and caused the colonists to rebel.

While the roots of the American Revolution lie in the French and Indian War that ended in 1763, if we are to look specifically at events from the 1770s that helped ignite revolution, three stand out.

The first is the Boston Massacre of 1770, in which British troops fired on Americans protesting their presence and killed five of them. The colonists were already upset at the presence of British troops in the colonies, and this event incited even more unrest and more call for British troops to leave the colonies.

The second was the Tea Act of 1773. This was not a tax, but a license for the British East India Company, which was in financial distress, to sell its tea at low cost in the colonies. The colonists saw this as a move that would undercut their own tea trade, and they also feared that it was opening the way for the British to impose more taxes on them by interfering directly in their commerce.

The third was the Quartering Act of 1774, which the colonists found "intolerable." This allowed British soldiers who, for whatever reason, could not be housed in their barracks to be billeted in American homes. As the Americans did not want the British troops in the colonies to begin with, having them in their homes was an even worse affront.

The Americans wished much less British control over their affairs, but with these three acts, the British appeared to be asserting more control. These acts incited tensions that were already high.

In the period after the French and Indian War, the colonies were going through what modern economists would call a recession. The colonists wanted to keep as much money at home as possible in order to maintain their local governments. Parliament had been passing tax laws for years but had not been enforcing them. When Parliament decided to end the policy of salutary neglect, the colonists grew angry and rebelled. While most colonists grumbled and paid the taxes anyway, the majority of the taxes, such as the Stamp Act, targeted a small, highly literate group of influential people who succeeded in stirring up anti-Parliament sentiment. These same influential people also resented the Proclamation Line of 1763, which was meant to keep the colonists out of the western territories. Land speculation was a major source of income for the rich in the colonies, and they resented any attempt to curb this enterprise. The colonists also fought against how they were treated by the British. While both sides were to blame for the Boston Massacre, the colonists quickly turned this into an anti-British propaganda tool. The colonists also did not like that smugglers were taken to Admiralty Courts rather than local juries. The colonists especially resented the Intolerable Acts, which closed the port of Boston. All of these things led to colonial anger; they rightfully claimed that they were being treated like second-class citizens.

There were many reasons behind the American colonies' decision to declare independence from Great Britain:

• The colonists believed that they were being taken advantage of and treated unfairly by the British, particularly after many tax laws were passed that negatively impacted the colonists. Additionally, the American colonies went unrepresented in Parliament, meaning that the colonists had no say in the tax laws passed or any other measure that may have affected them.
• The colonists did not like the restrictions placed on them by the British government, particularly the Proclamation of 1763, which prevented them from migrating west of the Appalachian Mountains in order to obtain cheap land. In addition to this restriction, the colonists were made responsible for paying for part of the costs of stationing the troops who enforce this Proclamation. 
• The Boston Massacre also incited anger and resentment after five colonists were killed at the hands of the British. This helped kick off a period of resistance that preceded the formal declaration of pursuing independence, including the staging of the Boston Tea Party as a means of protesting the Tea Act. Unfortunately for the colonists, the British tightened their grip with the introduction of the so-called "Intolerable Acts": the Boston Port Act (which closed the port of Boston until the colonists paid for the tea they had destroyed), the Massachusetts Government Act (which revoked Massachusetts' charter and placed it under the control of the British government), the Administration of justice Act (which ensured that royal officials being placed on trial would have those trials take place in Great Britain), and the Quartering Act (which permitted the governor to house soldiers in other buildings when quarters were not provided). 

Altogether, the increasing control that Britain attempted to exert over the colonies only backfired, resulting in their insistence upon freedom from what they considered to be tyranny.