strawberry-
Your professor is terribly misguided, and hardly a student of American History. Abraham Lincoln, an ardent reader of the bible an adherer of religious scruples, felt guided by none other than the bible for the civil war.
I urge you to read this article on the subject, by Britain’s outgoing chief rabbi:
http://www.ou.org/torah/article/the_slow_end_of_slavery
If you find that it may help some classmates in their faith, you can anonymously post this essay on the bulletin board, or in your classroom.