The Stamp Act of 1765 angered a lot of colonists and made them want independence, as many felt like they were being treated unfairly.
This act caused the colonists to pay taxes on certain paper products under Great Britain's rule. The colonists felt like this was very unfair as they had no say in what was happening, or "taxation without representation." They had nobody in the British Parliament and could not fight for what they wanted, many deemed this unfair.
Great Britain tried to justify this by saying that they were paying for the French and Indian War, which was very expensive, so they needed extra money. They also said that since they were giving the colonists protection by having British troops, so they shouldn't complain about what they were putting taxes on. This didn't matter to the colonists and many of them started to boycott the products that had taxes on them.
The Stamp Act of 1765 really unified the colonists together, as all of them wanted independence from Great Britain and believed they were being treated unfairly. After a while, Great Britain realized that the Stamp Act was hurting many British merchants and was doing more harm than good, so they repealed it.