Using the same logic as you used, then the US still has Slavery because people in its prisons are forced to work all of which is legal hence the State approves of it.
Similarly by that logic of yours the UK also had Slavery until the 20th Century since they had Indentured Servitude.
Oh yeah, and pretty much every single instance in any country (Communist China being a good example) were people were forced to move to the fields and work there is per your logic Slavery.
Correct. A slave by any other name is still a slave.