B
monroe doctrine stopped European colonization in the western hemisphere
The crusades strengthened the power of the. serfs in europe increased european isolation
The author of any textbook will say that there have been three major industrial revolutions. The first industrial revolution was steam industrial revolution, the second one based on coil and the production or major machines with the third happening recently where automated robots have starting to take over different jobs.
So they (the slaves) were treated bad because they weren't considered human beings
