The constitution strengthened citizen's right by providing protections for civil liberties like freedom of speech, the right to keep and bear arms, and the right to a fair trial, against government intervention. This protections are known as the Bill of Rights.
The constitution gave the president the power to command the armed forces in case of international war, and gave the Senate the power to declare wars and ratify treaties. This strengthened national security.
Finally, the constitution strengthened the economy by protecting people's property rights, which in turn promoted a market economy that fostered a dynamic system that brought economic growth and prosperity.
