The guess what be The Knights of labor *not sure if this is 100% correct*.
The Korean War was the first militarized instance of containment, as U.S. and South Korea fought against communist North Korea. ... When the UN Security Council voted to aid South Korea in stopping North Korean aggression, the U.S. agreed to send troops to the Korean Peninsula.
-Natural barriers - no influence or threat
-Nile river - provided annual floodings, fertile land, and communication
-Papyrus used to make a type of paper
-Access to metals
Answer:
Blacks were brought in as slaves to work on plantations.
