What was an argument used to try to justify slavery?

The southern economy hugely depended on the use of slavery.

Explanation:

One important argument the South saw reasonable and justifiable to not abolish slavery was its dependence for the growth of its economy. In other words, the South's economy was maintained due to the work of the enslaved.

The South's economy was agriculturally based. They did not have factories and large businesses like the North did. They relied on farms and the growing of crops. There were many farms and plantations with too many crops to harvest for the owner, and that's when slavery came in. Not only did Slaves work on farms and plantations, they did manual labor including construction.

Because the southern economy was heavily dependent on slavery, southern slaveholders fought hard to keep slaves. This argument was probably the most reasonable reason to keep slavery made by the South, although it is just as cruel as any other reason for servitude.

To summarize: the South's economy would not survive without slavery, and southern citizens would not make as much money without them.

- Acquaintance

There were multiple reasons why the South could justify part, white people during this time still believed in the natural superiority of their race. Blacks were seen as inferior, and made so by Nature or by God's judgment. Since that's the way it was, they believed that was the way God intended it. There were also many pseudo-sciences that still existed, arguing for natural ethnological hierarchies in the human species. Because blacks were deemed inferior, it was seen as only right that they served under the whites. There were also Biblical justifications for slavery.