Trade was the motivating factor. The silk road accross Asia was besieged by bandits & required bribes to a number of nations to transport goods to & from Asia. Therefore a sea route would be a much safer & less expensive means of getting trade goods to & from Asia.
Answer: The Underground Railroad work by giving slaves and place to stay. The slaves went from house to house with a light in a window. Most of the houses had secret areas or false floors and carts. The slave would either get in one of the false floor area or get in the cart.
Harriet Tubman was the leader of the underground railroad. She would tell the slaves a certain time to go to each house.
Manifest destiny and federal expansion
I believe it's camelot. Sorry if I'm wrong.
