Both historic and contemporary sources reveal that the terms “slavery” and “involuntary servitude” refer only to persons. In 1864, the term “slavery” was defined as “[t] he condition of a slave; the state of entire subjection of one person to the will of another.” .??.??. The clear language and historical context reveal that only human beings, or persons, are afforded the protection of the 13th Amendment.  Of course, PETA argued against the common sense of the ruling above, while SeaWorld was found innocent of enslaving whales.  More here…