Answer:
I believe it is "The labor demands of war industries caused millions more Americans to move--largely to the Atlantic, Pacific, and Gulf coasts where most defense plants located. "
Explanation:
I think it would be the diversification of races and culture that the United States have today. Immigration have changed and shifted United States in politics, economics, social and culture that enables the US to be what it is today. Diversification plays a significant role in the US because it shifted the policies of the country and it makes the country more flexible and achieve a level of prosperity and progress in all aspects.
The primary positive effect of the Columbian exchange was the introduction of New World crops, such as potatoes and corn, to the Old World. The most significant negative effects were the transmission of African populations into slavery and the exchange of diseases between the Old and New World.
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i hope this helped❤️
