White House says slavery is being taught wrong, should not be so negative

They're not wrong. They actually teach that slavery was abolished in the US..

Anyone expressing this opinion should be seconded to a chain gang for an undefined period of time. Could be a day, could be thirty-four months, could be for life. Reap the benefits of progress! Hope harder!

I think the case of "southern gentleman" Robert E. Lee shows the horrors of slavery. He inherited people as property from his father-in-law and refused to free them according to the will. They escaped his plantation under the understanding that they were legally emancipated:

Lee's more strict expectations and harsher punishments of the slaves on Arlington plantation nearly led to a revolt, since many of the enslaved people had been given to understand that they were to be made free as soon as Custis died, and protested angrily at the delay. In May 1858, Lee wrote to his son Rooney, "I have had some trouble with some of the people. Reuben, Parks & Edward, in the beginning of the previous week, rebelled against my authority—refused to obey my orders, & said they were as free as I was, etc., etc.—I succeeded in capturing them & lodging them in jail. They resisted till overpowered & called upon the other people to rescue them."

[...]

Wesley Norris himself spoke out about the incident after the war, in an 1866 interview printed in an abolitionist newspaper, the National Anti-Slavery Standard. Norris said that after they had been captured, and forced to return to Arlington, Lee told them that "he would teach us a lesson we would not soon forget". According to Norris, Lee had the overseer tie the three of them firmly to posts, and ordered them whipped: 50 lashes for the men and 20 for Mary Norris. Norris claimed that Lee encouraged the whipping, and that when the overseer refused to do it, called in the county constable to do it instead. Unlike the anonymous letter writers, he does not state that Lee himself whipped any of the enslaved people. According to Norris, Lee "frequently enjoined [Constable] Williams to 'lay it on well', an injunction which he did not fail to heed; not satisfied with simply lacerating our naked flesh, Gen. Lee then ordered the overseer to thoroughly wash our backs with brine, which was done."