How does the Monroe Doctrine demonstrate a shift from the traditional isolationism policy?

The Monroe Doctrine joined isolationism as a major part of United States foreign policy. It also told a hidden message. It told the world the United States wasn't weak group of states, but it had become a strong confident nation that was to be respected by the world.

Explanation:

on the morning of  july 21,  1861, general mcdowell ordered the  unionarmy to attack. it was on this hill that  confederate  colonel thomas jackson and his forces held back theunion  troops.

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