How did the differences between society in the South and society in the North help lead to secession?

How did the completion of the transcontinental railroad change the lives of american citizens? a-it increased the wealth of all americans and enabled them to travel more.b-it made cross-country travel too expensive for ordinary americans.c-it decreased the safety of americans who moved to settle the plains.d-it shortened travel time between the east and west for all americans.

During the eisenhower administration, the u.s. began to take an active military role supporting the government of o o a. south africa o b. burma (myanmar) o oc. finland od. south vietnam

Who was the fifth president of the u.s.