Why was it easy for the North to disrupt Southern transportation once the war began?

List three reasons why explorers began to explore new, and old areas. [[ps: doesn't explicitly say where. i think it's more in general.

Abody of water that is surrounded by land on three sides and leads to a larger body of water is called

The 20th amendment, also called the lame duck amendment, decreased the amount of time between the presidential election and the inaugration of the new president. what are the advancements that allowed for this amendment?