On the face of it, the Sugar Act of 1764 is kind of hilarious. This was technically a new tax, but the really important part, the part the colonists really objected to, was that there was an attempt to enforce it.

That's right. Until this point, the taxes in the colony existed…but they were just kind of ignored.

The Sugar Act was the unpopular sequel to the Molasses Act of 1733. That one expired (and was effectively ignored), and the Sugar Act was the replacement. Ironically enough, the Sugar Act halved the existing tax on molasses. But, you know, the colonists weren't actually paying that other tax, so it was, in effect, a huge increase.

Maybe more importantly, the Sugar Act made sure that certain colonial goods, like lumber, could only be sold to the British. Even with the shakiest understanding of economics, you'll know this is a bad thing to do for prices. Only one potential outlet? Then they're dictating the price.

To make matters worse, the Sugar Act (like the Stamp Act a year later) came in a time of economic depression. The Seven Years War pretty much messed up the economy for everyone— wars tend to do that—and while the crown needed a new tax the colonists definitely did not.