Why did the government feel the need to step in to supervise and regulate the railroads?

"the plan of removing the aboriginal people who yet remain within the settled portions of the united states . . approaches its consummation. . an extensive region . . has been assigned for their permanent residence. it has been divided into districts and allotted among them. many have already removed and others are preparing to go. . " removal of southern indians to indian territory, 1835 this passage is most closely related to a) imperialism. b) the civil war. c) westward expansion. d) the french indian war.

The zealots were for a: the teaching of jesus b: temple and sacrifices c: faith and law d: the military overthrow of roman rulers

What was the most explosive issue facing the united states prior to the start of the civil war?