what difference does the word "stealing" reveal

In the context of the story taking another man's slave was stealing. Both Huck and Tom want to "steal" Jim out of his little slave prison. Thus, the word steal takes on a greater irony. Can a human being be stolen in the first place? If he can a sense of ownership of said person is implied. Of course Tom and Huck wish to liberate their friend Jim but within the context of the American South at the time, slaves were considered owned.