Booker T. Washington (born c. 1858) had been a slave until the age of ten. He became an influential educator, orator and author. In his autobiography, Up From Slavery, he described several evils of the slave system. One was that it did not encourage family unity on the part of the slaves.
Another was that the white people would lose their motivation to master a trade. This led to a dependency by the white people on the slaves after the abolition of slavery.
A third evil was that the slaves would not be educated.
Fourth, because the slaves did not own the property they worked on, they didn’t care about it very much. Therefore, most properties fell into disarray.
Lastly, the slave system encouraged theft on the part of the slaves.