What were the key events that led to growing colonial support for independence?

The Sugar Act of 1764. This was the first attempt by the British to raise finance from the colonists to pay for their own defense. To that end, the British imposed a levy on exports of iron, lumber, and other goods. The measures were deeply unpopular with American colonists as they made it more expensive for merchants to engage in foreign trade.

The Stamp Act of 1765. Under the terms of the legislation, a tax was placed on all legal documents, newspapers, and pamphlets printed on watermarked or stamped paper. As with the Sugar Act, the stated purpose was to raise revenue to help defray some of the costs of the colonies' defense. But the colonists themselves were unhappy with the Stamp Act, seeing it as an attack on free speech, as disseminated through ideas and opinions in countless books, pamphlets, and newspapers.

The Townsend Revenue Acts of 1767. Named after the British Chancellor of the Exchequer this particular piece of legislation imposed duties on tea, glass, paper, and paint to help pay for administering the colonies. The duties were widely hated and colonial assemblies convened to condemn taxation without political representation in the British Parliament.

The arrival of British troops in 1768. This was seen by many American colonists as a provocative measure. Although the British government claimed to have sent troops to quell civil disturbances, opponents countered that this was more to do with suppressing popular dissent than with restoring order to the colonies.

The Boston Massacre of 1770. Simmering resentment over the stationing of British troops on American soil boiled over into a skirmish between a mob of citizens and a group of soldiers guarding the court house in Boston. Five civilians were killed after the soldiers fired into the crowd.
Last, but not least, the Boston Tea Party of 1773. Angered by the passing of the Tea Act, which exempted East India Company tea from import duties, a group of American patriots, disguised as Mohawk Indians, dumped £9,000 worth of East India Company tea into Boston Harbor.