The inhumanity of human beings toward other human beings is not a new story, much less a local story. There is no need to hide it, because there are lessons we can learn from it. But there is also no need to distort it, so that sins of the whole human species around the world are presented as special defects of "our society" or the sins of a particular race.
If American society and Western civilization are different from other societies and civilization, it is that they eventually turned against slavery, and stamped it out, at a time when non-Western societies around the world were still maintaining slavery and resisting Western pressures to end slavery, including in some cases armed resistance.
Only the fact that the West had more firepower than others put an end to slavery in many non-Western societies during the age of Western imperialism. Yet today there are Americans who have gone to Africa to apologize for slavery-- on a continent where slavery has still not been completely ended, to this very moment.
It is not just the history of slavery that gets distorted beyond recognition by the selective filtering of facts. Those who go back to mine history, in order to find everything they can to undermine American society or Western civilization, have very little interest in the Bataan death march, the atrocities of the Ottoman Empire or similar atrocities in other times and places.
Those who mine history for sins are not searching for truth but for opportunities to denigrate their own society, or for grievances that can be cashed in today, at the expense of people who were not even born when the sins of the past were committed.
An ancient adage says: "Sufficient for the day is the evil thereof." But apparently that is not sufficient for many among our educators, the intelligentsia or the media. They are busy poisoning the present by the way they present the past.