Answer:
because of technological changes and evolution of education.
Do you have a picture of this question
If a state law conflicts with the constitution or federal law, the constitution or federal law prevails.
Answer:
They basically just pushed out a bunch of native tribes from their homelands since they believed that it was their "God-given" right to expand westward and get more land space.
Explanation:
I mean I don't know if that's what you're looking for but that's all that you really need to know.
Basically, all of European and Asian economy was more or less ruined after the War while the United States were safe because their land was not destroyed. This was combined with the baby boom generation when suddenly a lot of young people began working and since the US was exporting like never before they needed factories and workplaces filled.