If you look at Ephesians 6 you'll see the obligation goes both ways.
One thing to consider (and it's not just regarding the bible) is that it's easy to fall into the "obviously slavery is wrong" trap. By our standards is it, but back ages ago it would not have been. Slavery was the economic basis for civilization. You can say it was wrong and I certainly would not like to see it return, however historical context really isn't optional in an objective analysis of other civilizations. Every civilization you can think of was built upon it. We wouldn't be having this conversation because we wouldn't have our own today. We built upon the Roman and Greek worlds which depended on getting things done and they didn't have machines. Animals were good for only a few things. That left people and having them do what they might not want to.
That of course is also somewhat simplistic. The reasons for slavery extended beyond that of course. It was also for punishment, entertainment, a great many things which were unrelated to getting work done. The treatment of slaves also varied greatly. They could be well treated, given proper food and rest, or they could be beaten, starved or often killed just because they were property. The bottom line is that slavery was the electricity, computers, oil and coal of the day. In a biblical context the emphasis was on humane treatment not abolition.