The Stamp Act was passed by Parliament in 1765 to raise money from the colonies, since it seemed only fair that they should pay part of the cost of their own defense. This was a tax essentially on all printed paper, including newspapers, playing cards, ship's papers, and all legal documents. This kind of tax was already in force in Britain, and the cost was relatively small to the colonists. But it was a burden, partly because payment was required in gold or silver coins, which were always in short supply in the colonies. The colonists felt there was no reason for a British army to be stationed in America, since, with the victory in the French and Indian War, the danger of the French was gone. Further, if this tax were allowed to continue, the precedent could be set that Parliament could tax the colonists without their own consent, since the colonies elected no representatives to Parliament. This would set a precedent that Parliament could tax the colonies at will. Patrick Henry introduced resolutions in the Virginia House of Burgesses denouncing the Stamp Act. Other colonial legislatures followed suit, and a Stamp Act Congress met in New York in 1765. Eventually, the cost of collecting the tax became higher than the revenue generated, so the act was repealed in 1766. However, Parliament passed the Declaratory Act, stating that they had the right to bind the colonies however they wished. (See the text of the Stamp Act.) (Read an essay on the Stamp Act.)
After the failure of the Stamp Act, the new Chancellor of the Exchequer, “Champagne Charlie” Townshend (pronounced town-zend; he was also known as “The Weathercock”), proposed to tax the American colonies (probably under the influence of a bumper of champagne). Since it was seen that a direct tax would not be well received, Townshend proposed tightening up the customs duties. The bills passed became known as the Townshend Acts. However, the main purpose of these duties was so much to raise revenue, but to assert Parliamentary control of the colonies. The revenue generated was used to pay the agents enforcing the duties, who were thus made independent of the colonial legislatures (and colonial bribes). This cut in to a cherished way of life, because many colonial merchants had grown rich on smuggling. The colonists, not finding a legal argument against customs duties, resisted by nonimportation agreements. Because the Townshend Duties were unpopular, both with the colonists and with British merchants, they were finally repealed. This happened on the same day as the “Boston Massacre.”
The Sugar Act (1764: also called the Revenue Act) actually was the earliest of these acts, was the first attempt to raise money in the colonies. Although the tax on molasses was cut in half, the act provided for strict enforcement. Since smuggling was a way of life in the colonies, the act cost £4 in enforcement costs for every £1 raised.
The Tea Act was actually not an attempt to raise revenue. In 1773, the British East India Company, due mostly to their own mismanagement, was on the verge of bankruptcy. To bail them out, Parliament passed an act allowing them to import tea directly to America, without paying the duty. Since the colonial merchants had stores of tea, some legal, on which they had paid a duty, but a lot smuggled from the Dutch, this would allow the East India company to sell tea at a lower price than the colonial merchants, including John Hancock, thus undercutting them and perhaps leading to their ruin. When the tea came to Boston harbor, it provoked the Boston Tea Party. This, in turn, let to an overreaction by Parliament, in passing the Coercive (or Intolerable) Acts, which included closing the port of Boston until the King was satisfied that the tea had been paid for. Further, more soldiers were sent to Boston. This then led to Lexington and Concord. Included by Americans in the Intolerable Acts, but not intended to be so by the British, was the Quebec Act. This allowed the inhabitants of Quebec to retain their French language, civil laws, and Catholic religion, and extended the boundary of Quebec to the Ohio and Mississippi Rivers. This infuriated the colonies (Massachusetts, Connecticut, New York, and Virginia) that claimed land in the area, and further united the colonies in their opposition to Britain.
Some of the information on this page is from USHistory.org.