Bruh you contradicted yourself. The north didn't have slaves.
They may not have been the majority in the whole US, but there were DEFINITELY more slaves than whites in the SOUTH, to the point where it got worrisome. Contrary to popular beliefs, revolts were on and popping. They realized they needed to stop bringing in new slaves and the cultural history they brought with them.
the North had slaves breh, don't believe that nonsense they had "informal" slavery even after they legally abolished slavery. there were areas and states that had black majorities (S. Carolina, Louisiana etc) but overall the population of N. America has always been predominantly white. the us/great britain stopping importing so many slaves because the population in the US could naturally increase. its all economics.