Most white Southerners historically throughout the time of enslavement in the United States thought it was acceptable and important for their way of life and economic development. They considered those who were held as slaves to be a property that they had the right to own and exploit for their own gain. A lot of people also thought that slavery was justified by moral and theological justifications, arguing that it was a necessary evil that helped to "civilize" and "Christianize" those who were enslaved.
The distinction between white Southerners who opposed slavery for moral and ethical reasons and those who actively campaigned to end it through the abolitionist movement must be made. However, most white Southerners at the time supported slaves and benefited from it.