Answer:
US immigrants created significant numbers of enclaves because of the hostility they faced (not the other way around). In the 1800s, unemployment levels weren't a significant concern relevant to this issue, and overpopulation worries weren't fully realized as a contemporaneous issue.
Answer:
Handling trade disputes. Monitoring trade policies. Technical assistance and training for developing economies. Cooperation with other international organizations.
Answer:
a.it was a big business in the railroad industry.