As proud as they were of the U.S. Constitution, the Founders did not assume their creation was perfect. Recognizing the text might need future changes, they outlined a clear and detailed process for amendments in Article V, which stated:

The Congress, whenever two thirds of both houses shall deem it necessary, shall propose amendments to this Constitution, or, on the application of the legislatures of two thirds of the several states, shall call a convention for proposing amendments, which, in either case, shall be valid to all intents and purposes, as part of this Constitution, when ratified by the legislatures of three fourths of the several states, or by conventions in three fourths thereof.

According to that text, amendments could be proposed by Congress or by the states, but either way, they then had to be ratified by the states, guaranteeing that only amendments with broad appeal could make it through the process. Once they passed through that gauntlet, however, amendments would be considered “valid to all intents and purposes, as part of this Constitution.” That means amendments become integral parts of the text, re-shaping the meaning of the document and its application to American political life.

In the eighty-fifth and last of the Federalist Papers, Alexander Hamilton cited the possibility of amendments as one of the Constitution’s greatest virtues. Conceding that honest observers could disagree about certain aspects of the document produced in Philadelphia, he emphasized its superiority to the Articles of Confederation, concluding, “I should esteem it the extreme of imprudence to prolong the precarious state of our national affairs, and to expose the Union to the jeopardy of successive experiments in the chimerical pursuit of a perfect plan” because “I never expect to see a perfect work from imperfect man.” Nevertheless, Hamilton argued it would be easier to pass the document and make changes afterward than to get everyone to agree to further changes before voting on ratification. Moreover, he argued that allowing the states to propose amendments would be a reliable barrier against an all-powerful central government—something they had just fought a war against the British to escape. As he put it, “We may safely rely on the disposition of the State legislatures to erect barriers against the encroachments of national authority.”

The possibility of adding amendments became crucial to ratifying the Constitution. After vigorous debates in the state ratifying conventions, moderate Anti-Federalists (those who criticized the Constitution but who were willing to imagine compromises in order to ratify it) demanded amendments guaranteeing specific individual and state’s rights. In several states, including influential Massachusetts and Virginia, votes in favor of ratification depended on just such a promise. Hamilton had recognized the demand for a Bill of Rights in the Federalist Papers (though he reminded critics of the Constitution that the Articles of Confederation did not have one either). Although he was skeptical about specific amendments, he did not oppose the idea of passing them after ratification. Hamilton’s political rival Thomas Jefferson agreed, writing in December 1787: “A bill of rights is what the people are entitled to against every government on earth . . . and what no just government should refuse.”

When the new federal government was finally in place, Speaker of the House James Madison used his prestige as one of the Constitution’s primary authors to ensure that the Bill of Rights eventually became the first ten amendments to the Constitution, ratified in 1791.

These amendments placed specific limits on the federal government’s powers and guaranteed important individual rights:

• The First Amendment set the tone, declaring that Congress “shall make no law” restricting the freedoms of religion, the press, speech or assembly;
• The Second, citing the importance of a “well-regulated militia,” protected “the right to keep and bear arms;”
• The Third protected the people against being forced to quarter troops in peacetime;
• The Fourth guaranteed protection against “unreasonable searches and seizures;”
• The Fifth protected against self-incrimination;
• The Sixth guaranteed the right to a speedy trial and legal due process;
• The Seventh protected against double jeopardy;
• The Eighth forbade “cruel and unusual punishments;”
• Then, just to be sure…
  • The Ninth declared: “The enumeration… of certain rights shall not be construed to deny or disparage others retained by the people;” and
  • The Tenth promised that powers “not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people.”

Since that initial flurry of amendments over two hundred years ago, the Constitution has only been amended seventeen more times. Those amendments can be combined into three broad categories:

1. Procedural Amendments that modified the election and term limits of the President (XII, XX, XXII, XXV) or the Senate (XVII); and which clarified issues of judicial or congressional authority (XI; XXVII)
2. Amendments that encouraged greater equality and individual freedom, such as those that abolished slavery (XIII); promised all citizens equal protection under the law (XIV); and guaranteed the right to vote to previously disenfranchised groups such as African Americans (XV), women (XIX), and all citizens over the age of 18 (XXVI)
3. Amendments that resolved constitutional questions such as whether the federal government could levy an income tax (XVI), abolish the poll tax (XXIV), and grant residents of the District of Columbia the right to vote for President (XXIII)

Finally, one amendment (XVIII), which prohibited the sale of alcohol, was repealed by another amendment (XXI) fourteen years later.

The Constitution was intended to be a living document, open to change, though only when enough Americans believe a desired policy cannot be pursued within the normal course of legislation. That’s why the bar for approval is set so high, and why amendments are relatively rare.

Current proposed amendments, such as the Equal Rights Amendment, which guaranteeing equal rights regardless of gender, or the Balanced Budget Amendment, requiring Congress to maintain a balanced federal budget, have been subjects of ongoing debate. Neither, however, has yet gained the necessary approval for ratification.

Whether or not they are ever ratified, the simple possibility of amending the Constitution remains a crucial element of the Founders’ vision. Even as they designed a government to stand the test of time, allowing amendments to reflect changing national priorities endures as one of the most valuable tools with which “We the People” can live up to our most solemn task—to continuously “form a more perfect union.”