During the industrial revolution, American businesses started to used modern machines to replace the existing manual labor. This made using slaves no longer as profitable as it used to.
As a result, people started to give support to abolish slavery. But this support tends to be coming from the northern states. At that time, the southern states were not as willing to adopt the technology from the industrial revolution. This made the southern states still reliant on slaves. This is what caused the conflict that leads to the civil war
