9. C
10. C
11. A I believe
12. D
They came from Europe because America had a booming economy.
Answer:The U.S. remained neutral until 8 December 1941, when it declared war on Japan in response to the surprise attack on Pearl Harbor the previous day
Explanation:
Because they didn’t explore the rest of the us yet
I think that 1=B and 2=J and 7=H