Willem van de Velde the Younger, Dutch ships in a calm. Public domain.
The Sugar Act cut the duty on foreign molasses and then set up courts and paperwork so merchants would actually pay it.
A household that bought rum never saw the statute, but the duty sat in the price once the distiller had to pay.
A coastal merchant who had ignored the earlier molasses duty now faced bonds, papers, and a court without a jury.
British sugar planters still wanted a protected market, and the Treasury wanted a rate low enough that merchants would pay it.
The American Revenue Act of 1764 set the duty on foreign molasses at three pence a gallon and was written to be collected, with heavier paperwork and trials in vice-admiralty courts.
It also added colonial products to the list that had to pass through Britain.
Merchants understood that a smaller duty, taken in fact, cost more than a larger duty nobody had been paying.
American Revenue Act, 4 George III c. 15 (1764)