Berlin Blockade: 1948
Korean War: 1950
NATO Formed: 1949
Truman Doctrine: 1947
Hi Brainiac
Because they believed that feed slaves would be willing to take lower wages in order to get work in North.
Sorry for the late answer, but I hope its help:)
Answer:
What was the answer to California's isolation problem?
<h2><em><u>
Building a railroad.</u></em></h2>