1930 to 1941...............
Yes, that's in fact true.
Answer:
Obstacles:
1.The sea, america would normally be hard to access for non-mexican immigrants due to the wide ocean blocking their way. They often take this dangerous journey across as they have no other choice.
Pull factors:
1.For most non-americans (like me), the country would probably be fantasized and thought to be a great modern country full of amazing opportunities. This may make them wish to immigrate to America.
This policy is known as COLONIZATION.
Colonization refers to the action of settling down among foreign indigenous people and establishing control over them. Politically, this action is usually carried out by powerful countries. The Europeans were able to colonize Africa, America and India.