Answer:
Article IV addresses something different: the states' relations with each other, sometimes called “horizontal federalism.” Its first section, the Full Faith and Credit Clause, requires every state, as part of a single nation, to give a certain measure of respect to every other state's laws and institutions.
Explanation:
One of the most important was climate changes. As climate changed, nomads had to find new places to migrate to which led to people going to areas that were uninhabited before. Another was the development of agriculture which more or less ended the nomadic way of life when people started settling.
Roosevelt was disappointed and Hoover was worried cause he didn’t know how to fix the depression