They were successful because their goal was to get rid of slavery and have the union win the civil war. They were able to get the 13th amendment passed (with the bribery of some Democrats) and win the civil war in four years.
Are there choices for this question?
B. If the German air force won, the German army could invade Britain
Chinese immigrants were cast as outcasts in Californian society, because of cultural differences - customs, clothing, beliefs, food, language etc -. The response to those differences caused Chinese immigrants to form their own community called Chinatowns.
Nativists thought Chinatowns were dangerous but necessary to help Chinese immigrants to assimilate, they also thought Chinatown was useful because it was used to separate immigrants from other residents.