How the Constitution gets amended
The founders made the Constitution hard to change on purpose. A document that could be rewritten with every election would not be worth very much. In 236 years, the Constitution has been amended 27 times. The last amendment was ratified in 1992 -- ratifying a change originally proposed in 1789.
Article V: two paths to proposal, two paths to ratification
The Constitution provides two ways to propose an amendment and two ways to ratify one. Proposals can come from Congress, with a two-thirds vote of both the House and Senate -- this is how all 27 amendments so far have been proposed. Or they can come from a constitutional convention called by two-thirds of state legislatures -- this has never happened. Ratification requires three-fourths of state legislatures (38 states) or ratification conventions in three-fourths of states -- the latter has been used exactly once, for the 21st Amendment, which repealed Prohibition.
Why this is so hard
The supermajority requirements are not an accident. They reflect the founders' belief that the fundamental law of the land should only change when there is broad, durable national consensus -- not when one party wins an election. At a 60-40 partisan split in both chambers, you cannot amend the Constitution. You need to convince a meaningful portion of the other side. This has two consequences: amendments that pass have genuine staying power, and amendments that fail often reflect a society that has not yet resolved its underlying disagreements.
The Bill of Rights
The first ten amendments -- the Bill of Rights -- were ratified in 1791, three years after the original Constitution. Several states refused to ratify the Constitution without a promise that a bill of rights would follow. James Madison, who had initially doubted the necessity of such a document, drafted the amendments and pushed them through the first Congress. They codified rights that had deep roots in English common law and colonial practice: freedom of speech and religion, protection against unreasonable searches, the right to a jury trial, and the reservation of unenumerated powers to the states and the people.
The Civil War amendments
The 13th, 14th, and 15th Amendments were ratified between 1865 and 1870, transforming the Constitution after the Civil War. The 13th abolished slavery. The 14th established birthright citizenship, guaranteed equal protection of the laws to all persons, and prohibited states from denying due process. The 15th prohibited denying the vote based on race. These three amendments were ratified while the former Confederate states were under military occupation, and the Southern states were required to ratify the 14th as a condition of readmission to the Union -- a contested chapter of amendment history that scholars still debate.
The 17th Amendment
Before 1913, U.S. senators were chosen by state legislatures, not by direct popular vote. The original design reflected the founders' view of the Senate as a body representing state governments rather than individual citizens. The 17th Amendment changed this, establishing direct election of senators by the voters of each state. It was driven by a Progressive Era reform movement that had documented widespread corruption in the legislative selection process and believed direct democracy would produce more responsive, less corrupt senators.
The 27th Amendment
James Madison originally proposed what became the 27th Amendment in 1789 as part of the same package that became the Bill of Rights. It prohibits Congress from giving itself a mid-term pay raise: any pay increase can only take effect after an intervening election. The amendment was ratified by only six states at the time and then forgotten. In 1982, a University of Texas undergraduate named Gregory Watson discovered that the amendment had no ratification deadline and began a one-man campaign to get state legislatures to ratify it. A decade later, 38 states had done so. It was certified as part of the Constitution in 1992 -- 202 years after it was proposed.