You will actually find a long list of grievances that many of the American colonists had against the king in the Declaration of Independence itself. Thomas Jefferson wanted to make it clear that they had good reasons to rebel against Great Britain. Some of the major grievances are described below.
One significant grievance had to do with limits put on commerce. For much of the history of the colonies, the British imposed a policy known as salutary neglect. This essentially meant that they ignored laws that restricted trade within the colonies as long as the colonists were not causing any overt trouble. Beginning in the 1760s, however, the British began enforcing a policy that did not permit colonists to trade directly with markets outside of the British Empire. Many colonists—notably John Hancock, who made a fortune through trade—saw this as putting limits on their rights as free citizens.
Another grievance had to do with restrictions on where the colonists could settle. The French and Indian War was fought largely for control of the Ohio River Valley. When the British won the war, many colonists were eager to claim that land and move west of the Appalachian Mountains. However, the Royal Proclamation of 1763 forbade the colonists from settling there. Many thought this was a betrayal by the king, given the role that the colonists played in winning the war.
Even though the French and Indian War was over, the British continued to keep a large number of soldiers in the colonies. Many colonists chaffed at this. In Boston, many were very upset that British soldiers were also moonlighting at local jobs. There was not enough work to go around as it was. It was a protest over this that ignited the so-called Boston Massacre of 1770.
One thing that enraged many colonists was the revocation of the Charter of Massachusetts. In response to the Boston Tea Party, the charter of that colony was revoked, and the British military was put in charge of the colony. To make matters even worse, the Port of Boston was closed, strangling the livelihood of many New Englanders. This was all part of what was known as the Intolerable Acts. Colonists throughout North America saw this as a direct infringement of their rights as a free people.
Beginning in the early 1770s, colonists accused of certain crimes were transported to England for trial. This meant that they did not have access to a fair defense and evidence in their favor that might only be available back in the colonies. Many times they were deprived of trial by jury, something that they saw as one of their fundamental rights as Englishmen.
Another grievance had to do with the seizure of weapons. For generations, colonists had formed local militias to safeguard their defense against hostile French and Native Americans. However, beginning in 1774, the British authorities in Massachusetts saw this as a threat to their control and began seizing gunpowder stores. It was an attempt to seize the gunpowder in Concord that set off the first battle of the American Revolution.