Answer:
The Reagan Era or age of Reagan is periodization of recent American history used by historians and political observers to emphasize that the conservative “Reagan Revolution” led by President Ronald Reagan in domestic and foreign policy had a lasting impact
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Explanation:
1. Federalism
2. The U.S. Constitution
3. Checks and Balances ( The legislative,Executive, Judicial Branch)
4. Popular Sovereignty
Harry S Truman is your answer
The answer is b need 20 characters
I would say A primary source...