Which body of water is located south of the Coastal Plains in the United States and acts as a border between Mexico and the United States?

Idon't really understand the question. it counts for 20% of my lesson grade and i really need putting the answer into words. anything will . i need asap so im awarding 30 points.a disagreement between states of the united states concerning the rights of states vs. the authority of the national government led to the civil war. state governments were forced by war into a subservient position. what might happen if national governments ceded their authority to a world government by international treaty?

What is one way scalawags were significant during the reconstruction in the south?

Explain in detail why hitler had over 6 million jewish people killed during the holocaust and why