Final answer:
The Constitution sets up the structure of the American government, establishing the legislative, executive, and judicial branches and defining their powers. It also includes provisions to protect individual rights and maintain a balance of power between federal and state governments.
Step-by-step explanation:
The Constitution of the United States serves several key purposes. Primarily, it sets up the structure of the American government by establishing the three branches: legislative, executive, and judicial. It outlines their powers and the system of checks and balances that ensures no single branch can dominate. Moreover, the Constitution defines the scope of federal power and the fundamental rights of citizens through its amendments. Notably, the power to create rules for trading with foreign nations is encapsulated within the broader structure of government powers granted by the Constitution. It is important to understand that the Constitution followed the Articles of Confederation, which provided a much weaker federal structure, unable to impose taxes or command a standing army effectively. The Constitution clearly strengthens the central government compared to the Articles but also aims to protect the rights of states and individuals.