What is the theme in Prentice Alvin by Orson Scott Card?

Another theme in the book is the fight against slavery. One of the major conflicts in this book is caused by slavery, which is legal in most of the southern states. Along the border, it is considered shameful to be an emancipationist, and it is illegal to help escaped slaves, instead of returning them to their masters. The slave masters profit richly from the slaves, as the first page so poetically says, "They calculated a way of turning each bead of a Black man's sweat into gold and each moan of despair from a Black woman's throat into the sweet clear sound of a silver coin ringing on the money-changer's table."