Because the South was mainly farms that had to be worked by hand, while the North was more industrialized and had more factories. The white Southerners did not want the slaves to be freed because they wouldn't have free labor and would be forced to pay workers to work their fields.
The correct answer here is Asia, Africa and Europe.
The Silk Road is one of the most important trading networks that ever existed in the history of mankind and it is preserved as UNESCO World Heritage Site. It connected the East and the West and it was central for both the economic and cultural interaction between two parts of the world.
Andrew Carnegie founded the Bessemer Process, which quickened the steel making process. He also used Vertical Integration to corner the steel market.
