Answer:
1) Americans feared communism because communism in other nations caused people to not own land, follow their beliefs, and they weren't allowed to speak out. This is why communism was a scary thing at the time.
2) The stock market was successful because when the stock market rose the economy also started to rise.
3) Americans were hostile towards Immigration because they thought that the Immigrants would take over Americans jobs. This made the Americans angry towards the Immigrants.