The right answer is molasses.
Making rum from molasses, a syrup derived from sugarcane, was quite profitable. So, in 1733 the British government passes The Sugar and Molasses Act, a tax of six pence per gallon on molasses which was imported from the French West Indies or the Dutch West Indies. The main goal of this tax was to regulate trade and promote commerce with the British West Indies. Grenville recognized that the long-neglected molasses tax if enforced would devastate a major colonial industry. So he put through the American Revenue Act of 1764, commonly known as the Sugar Act, which cut the duty on molasses in half.
