Many people were involved in this system, from the warring tribes in Africa selling prisoners, to countries like the UK setting up colonies with slaves for cotton, tobacco, etc.
We were the colony that finally stopped the system. It took a long time and a lot of blood because it was the system, but it was ended.
Given that the enslaved had been so subjugated by others of the very same race, how could the institution itself possibly be called essentially racist?
Or if you'd like a quick answer from the Confederacy's Vice President, you might read the Cornerstone Speech, which includes these words: "Our new government['s]...foundations are laid, its cornerstone rests upon the great truth, that the negro is not equal to the white man; that slavery—subordination to the superior race—is his natural and normal condition. This, our new government, is the first, in the history of the world, based upon this great physical, philosophical, and moral truth."
If you're having trouble seeing the racism there, I'm not sure how else I could help.
If even you could somehow make a convincing argument that the pre-war system was not inherently racist (which you cannot), the post-war system of neoslavery would put the final nail in that coffin.
Even an answer of zero doesn't address or contradict my original point.
There's no such thing as "neoslavery". Racism was certainly used after the war to reduce labor solidarity between the white working class and the newly-freed black laborers, however, that fact also doesn't address or contradict my original point.
Maybe try suggesting some serious historical scholarship instead of ideologues.
For those more reasonable who want to know about what anti-racism is opposed to, I'd suggest reading Loewen's Sundown Towns, Kendi's Stamped from the Beginning, and Mills's The Racial Contract as beginner-friendly looks at the system of racism, its historical and intellectual roots, and how it all played out historically.