Bob is the best one in the whole
Because once an indentured servants time is up, you have to let them live their own life, but if you have a slave, you literally own them and keep them until they die if you choose to do so.
After the civil war there was a huge surge to rebuild the infrastructure of the U.S. many Americans wanted to move west to escape the horrors of the civil war, which started the race to the west coast (intercontinental railroad)