What does the Constitution do?

The Constitution sets up the structure of the federal government and protects the basic rights of the American people. The Preamble announces six purposes: to form a more perfect Union, establish justice, insure domestic tranquility, provide for the common defence, promote the general welfare, and secure the blessings of liberty to ourselves and our posterity. The body of the document then carries those purposes into action through seven articles.

Article I creates a bicameral Congress of a Senate and House of Representatives, lists its enumerated powers, including the powers to tax, borrow, regulate interstate and foreign commerce, declare war, raise armies, coin money, and pass laws necessary and proper to carry those powers out. Article II vests the executive power in a president elected for a four-year term through the Electoral College, lays out the duties of commander-in-chief, treaty-making, appointments, and the obligation to take care that the laws be faithfully executed. Article III creates one Supreme Court and authorizes Congress to establish lower federal courts, defines the cases they may hear, and guarantees jury trials for federal crimes. Article IV governs interstate relations and admission of new states, Article V provides the amendment procedure, Article VI contains the Supremacy Clause and bars religious tests for office, and Article VII set the original ratification rules.

Beyond setting up government, the Constitution protects basic rights through specific provisions like the writ of habeas corpus, the prohibition on bills of attainder and ex post facto laws, jury trial guarantees, and the bar on titles of nobility. The first ten amendments, ratified December 15, 1791 as the Bill of Rights, added explicit protections for speech, religion, assembly, due process, and trial rights. Later amendments abolished slavery, required equal protection of the laws, extended voting rights, and limited presidential terms.

The Constitution thus does two complementary jobs at once. It builds a working national government with enough power to function, and it walls off zones of individual liberty that even popular majorities and elected officials cannot cross. Every law, regulation, and government action in the United States must operate inside that frame.