Answer: the south
Step-by-step explanation:
When america was first founded, the south was used for resources on farms and plantations and the north was more industrialized, using factories and such to make different products. Due to the fact that plantations are very large plots of land and the south had a high demand for different resources such as cotton and rice, the owners needed help and so they used slaves to do their work. Being that slaves were treated like property, they were paid either very poorly or not at all so it ended up giving the land owners a huge profit. They make a lot of money from their products and they don't spend it on paying workers. Therefore, if slavery was abolished, the owners would not fulfill the demand of the people and they cannot work efficiently on the large plot of land by themselves, which would lead to a large drop in personal income.