I partially understand your point, but I don't think "free" is necessarily a better description than "slave". One is always free in a literal sense to choose b

I partially understand your point, but I don't think "free" is necessarily a better description than "slave". One is always free in a literal sense to choose between available options (e.g. a slave may choose to escape, an employee to quit). However, ability of a second party to attach consequences to those options (e.g. corporal punishment or death, deportation away from one's family, removal of healthcare from sick loved ones, etc.) amounts to restricting the freedom of the individual. I don't accept that legal freedom equates to practical freedom, e.g. you have the legal right to quit your job therefore in a practical sense you are completely "free" to quit your job. If your employer can attach extremely negative consequences to quitting, then your freedom has been severely limited. I also have trouble with arguments that the choice to immigrate was made of free will, therefore all consequences are one's own responsibility. It's not legal nor ethical to allow people to "freely choose" to sign themselves into slavery. Anyway, this is obviously a contentious and charged issue, but I hope this helps communicate a different perspective.