These and other arguments fought for the rights of the propertied elite against what were perceived as threats from the abolitionists, lower classes, and non-whites to gain higher standards of living. The economic self-interest of slaveholders certainly played a role, as slaves represented a massive amount of wealth – at the time of the Civil War some historians estimate the over 20% of private wealth in the US was slaves. They saw the abolition of slavery as a threat to their powerful Southern economy: an economy that revolved almost entirely around the plantation system and was supported by the use of black slaves.