There's lies, damned lies, and statistics. Pop singer John Legend got into the numbers game when he received an Oscar for a song he composed for the movieSelma. He stated that the number of black males under the control of the criminal justice system in the US was comparable to the number of black male slaves in 1850.
OK, first of all, since he was talking about racial justice which was the theme of the movie Selma, I think that's AOK. If he had gone off on bullying, transgender stuff, vegetarianism, etc., that would have been off topic, so no problem there here.
But his numbers were kinda weird. The Washington Post went over the numbers and said he was "mostly right". They have the video there, too.
First of all, I was amazed at how many of the slaves were female in 1850. With 3.2M slaves less than 1M were male. You'd think the guys would be happy!
OTOH only about 10% of the black people were free.
While Legend was close on raw numbers, no blacks are officially enslaved in America today and only about 1-2% are incarcerated. I don't have any idea what the incarceration rate was in 1850. Actually I'm not sure of any of my numbers since the sites that cite such numbers are all trying to make some kind of point. The US does have one of the highest incarceration rates in the world with Seychelles and maybe North Korea being higher.
Overall, I would say equating black life in America today with America 165 years ago doesn't add up.