Disagree.
If America as a nation stands for anything, it's the primacy of human freedom and equality.
Chattel slavery is the utter negation of those principles, therefore it is (was) by definition the most anti-American of all possible institutions.
The present deplorable condition of so many black Americans can be reversed in any individual family simply by refusing to participate. Slavery denied that choice to individuals, and families in any meaningful sense of the term could not exist under slavery.
Some slave manned plantations had more liberal (in a good sense) policies and allowed their slaves to have side businesses and to buy themselves free. Some allowed marriages and families that were preserved as a group. This was due to Christian morality, which some masters honored more than others depending on their personal convictions.