It's not comparable to the holocaust but it's comparable to what Nazi Germany did.

the Nazis came in power in 1932 and concentration camps came very soon after that. For first they were facilities where criminals and "criminals" spent a fixed time, after which they were always released. Eventually the system got gradually converted into what the US system is currently like. And then they went onwards, inventing the concept of death camp in 1941.

(Also good to keep in mind that "only" half of people murdered in concentration camps were Jewish. The holocaust was, in all its horror, only one part of the system of murder.)