The Constitution at a Glance: the Preamble and Seven Articles
The Constitution is organized more simply than its reputation suggests. There is a one-sentence preamble, then seven numbered Articles, and then the amendments added since 1791. The Articles are not equal in length or ambition. The first is longer than the next three combined, and the last is a single sentence.
What follows is a plain-language tour of that structure. Treat it as a map rather than a substitute for the text: read the map, then read the clauses themselves in the Constitution Annotated, which sets each provision beside a summary of how courts have applied it.
The Preamble
Fifty-two words, one sentence, and not a single grant of power:
We the People of the United States, in Order 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, do ordain and establish this Constitution for the United States of America.
Courts have consistently treated the Preamble as a statement of purpose rather than a source of authority. No branch of government can point to "the general Welfare" here and claim a power the rest of the document does not give it. Its real work is declarative. The charter is issued in the name of "We the People," not of the states as such, and that phrasing was noticed and argued over during ratification.
Article I: the Congress
Article I is the longest by a wide margin, which is itself a statement about what the framers expected the government mostly to be doing. It creates a legislature of two chambers: a House of Representatives elected every two years and apportioned among the states by population, and a Senate of two members from each state serving six-year terms.
Senators were originally chosen by state legislatures, and direct election arrived only with the Seventeenth Amendment in 1913. Apportionment of the House originally counted enslaved people as three-fifths of a person for both representation and direct taxation, a compromise that increased the political weight of slaveholding states and was not removed from the text until the Fourteenth Amendment in 1868.
Section 8 is the heart of the Article: the list of things Congress may do. Tax and spend, borrow money, regulate commerce with foreign nations and among the states, establish uniform rules of naturalization and bankruptcy, coin money, create post offices, secure patents and copyrights, define piracy, declare war, raise armies with military appropriations limited to two years at a time, maintain a navy, and make all laws "necessary and proper" for carrying those powers into execution. That last clause has generated more argument than any other sentence in the Article.
Sections 9 and 10 are the limits. Congress may not suspend habeas corpus except in cases of rebellion or invasion, may not pass bills of attainder or ex post facto laws, may not grant titles of nobility, and may not spend money without an appropriation. Section 9 also barred Congress from prohibiting the importation of enslaved people before 1808. Section 10 forbids the states to make treaties, coin money, or impair the obligation of contracts. Both chambers publish accessible explanations of how they work today, from the Senate's origins and foundations pages to the House explained.
Article II: the presidency
Article II is remarkably short for the office it creates. It vests "the executive Power" in a single President serving a four-year term, chosen by electors appointed by each state in whatever manner its legislature directs, and it sets the eligibility requirements: at least thirty-five years old, a natural-born citizen, and fourteen years a resident.
The enumerated powers are few. The President is commander in chief of the armed forces, may require written opinions from the heads of executive departments, may grant reprieves and pardons except in cases of impeachment, makes treaties with the advice and consent of two-thirds of the senators present, and appoints ambassadors, judges and other officers subject to Senate confirmation. Section 3 adds the duties: report to Congress on the state of the union, receive foreign ambassadors, and "take Care that the Laws be faithfully executed." Section 4 provides for removal on impeachment for and conviction of treason, bribery, or other high crimes and misdemeanors.
Almost everything else about the modern presidency, including the departments, the agencies and the staff, was built later by statute on top of that short foundation. How much independent authority the sparse text confers is one of the durable disputes in constitutional law, and it is a good example of a question this site describes rather than settles.
Article III: the courts
Article III establishes "one supreme Court" and leaves the rest of the federal judiciary to Congress, which may create lower courts as it sees fit. Judges hold their offices "during good Behaviour," effectively for life and subject to impeachment, and their salaries cannot be reduced while they serve. Both provisions exist to insulate judges from pressure.
Section 2 sets out what federal courts may hear: cases arising under the Constitution, federal laws and treaties, along with certain disputes between states, between citizens of different states, and involving foreign parties. It also guarantees jury trial in federal criminal cases. Section 3 defines treason, the only crime the Constitution itself defines, as levying war against the United States or adhering to their enemies, and it requires either two witnesses to the same overt act or a confession in open court. That deliberate narrowness was a reaction to centuries of treason charges used against political opponents in England.
Notice what is absent. The text nowhere says in so many words that a court may refuse to enforce an unconstitutional statute. Where that power came from is the subject of judicial review.
Article IV: the states and their relations
Article IV governs how the states deal with each other and with the national government. The full faith and credit clause requires each state to respect the public acts, records and judicial proceedings of the others, which is why a judgment entered in one state can be enforced in another. The privileges and immunities clause bars a state from treating citizens of other states as second-class visitors, and an extradition clause requires the return of fugitives from justice.
Article IV also contained a clause requiring the return of enslaved people who escaped across state lines. It was made void by the Thirteenth Amendment in 1865. Section 3 governs the admission of new states and the management of federal territory. Section 4 guarantees every state "a Republican Form of Government" along with federal protection against invasion and, on request, against domestic violence. The division of authority all of this implies is explored further under federalism.
Article V: changing the document
Article V is one long sentence describing how the Constitution may be amended: proposal by two-thirds of both houses of Congress or by a convention called at the request of two-thirds of the state legislatures, followed by ratification by three-fourths of the states. It is demanding by design, and it has been completed twenty-seven times. The mechanics, including the routes that have almost never been used, are set out on our page about the amendments.
Article VI: supremacy, debts and oaths
Three short clauses, each consequential. The first assumes the debts contracted under the Articles of Confederation, reassuring creditors that the new government would honor the old one's obligations. The second is the Supremacy Clause: the Constitution, federal laws made under it, and treaties are "the supreme Law of the Land," binding state judges regardless of contrary state law. The third requires federal and state officers to swear an oath to support the Constitution, and then adds a sentence that was unusual in 1787: "no religious Test shall ever be required as a Qualification to any Office or public Trust under the United States."
Article VII: ratification
The shortest Article, and the one that made the rest operative. It provides that ratification by conventions in nine states is sufficient to establish the Constitution among the states so ratifying. Nine was reached when New Hampshire ratified in June 1788. The document was signed in Philadelphia on September 17, 1787, and the National Archives holds the original, with transcripts and images available through its founding documents collection.
What to notice on a first read
Three things tend to surprise people. The first is proportion: Congress gets far more text than the presidency and the courts combined. The second is silence. There are no political parties in the document, no cabinet by that name, no mention of judicial review, no right to privacy in those words. The third is sequence. The structure came first and the rights came after, which means the guarantees most people think of as the Constitution arrived in 1791 with the Bill of Rights.