Railroad expansion helped industrial growth because people were able to go more places easier so people and industries became more spread out through out the lands.
A. The Nullification Crisis led to the promotion of federal power over states' rights.
It was actually outlined in the constitution that states could nullify laws, etc., they deemed that were wrong. However, when South Carolina decided to nullify a law, Andrew Jackson put a stop to it, causing the crisis and almost starting the war then and there. When, prior to the event, states still had a substantial amount of power, President Jackson's response caused states' rights to diminish under the authority of the federal government.
The Vietnam war. He led us into the Vietnam war
Because as a gesture of unity, they combined to create a national union ticket.
The answer is actually C i just answered it on usatestprep.