The Sugar Act

The Sugar Act was passed by Parliament on April 5, 1764, and it arrived in the colonies at a time of economic depression. It was an indirect tax, although the colonists were well informed of its presence. A good part of the reason was that a significant portion of the colonial economy during the Seven Years War was involved with supplying food and supplies to the British Army. Colonials, however, especially those affected directly as merchants and shippers, assumed that the highly visible new tax program was the major culprit. As protests against the Sugar Act developed, it was the economic impact rather than the constitutional issue of taxation without representation, that was the main focus for the Americans.

New England especially suffered economic losses from the Sugar Act. The stricter enforcement made smuggling more dangerous and risky, and the profit margin on rum, so the colonists argued, was too small to support any tax. Forced to increase their prices, many Americans, it was feared, would be priced out of the market. The British West Indies, on the other hand, now had undivided access to colonial exports and with supply well exceeding demand the islands prospered with their reduced expenses while all New Englanders saw the revenue from their exports decrease. The foreign West Indies had also been the primary colonial source for specie, and as the reserves of specie were depleted the soundness of colonial currency was threatened.

http://en.wikipedia.org/wiki/Sugar_Act