Another Question on the Three-Fifths Compromise

I’ve been reading that the 3/5ths compromise was a concession by the North because they wanted the Southern delegates to approve Congress’ power to regulate commerce.

Why would the South have been against giving the Congress power to regulate commerce in the first place?

Gosh, almost makes me want to take a history class.

The South was heavily dependent upon imported goods (if not totally dependent). Its main exports, cotton and other crops, were usually carried out in British ships. In the North, there were American ships that carried American-made goods.

The South feared that if Congress were allowed to regulate commerce, it could restrict it to the point where foreign ships would be prohibited from entering US ports.

There was also the problem of whether or not Congress could regulate the slave trade.