The Constitutional Amendments numbered 11 through 27 are the true amendments to the Constitution, since the attachment of the first 10 amendments (known as the Bill of Rights) was necessary to secure its ratification. They represent the first and most recent instances where circumstances of sufficient importance arose to require amending the document, and they illustrate the document as a living framework designed to sustain the nation indefinitely.
The Constitution is intentionally difficult to amend in a deliberately slow process that incorporates safeguards against extreme reactions to events of temporary importance. After each house of Congress passes an amendment with a two-thirds supermajority, the legislatures of three-fourths of the states must pass the pending amendment verbatim before it becomes ratified as an amendment. Pending ratifications date as far back as 1790.
The 11th amendment, ratified in 1795, clarifies the role of the Supreme Court in interstate suits. Amendments 13 through 15, 19 and 24 abolish slavery, establish rights of citizenship and due process, protect voting rights, and grant women suffrage, respectively. The 16th amendment establishes a federal income tax. Amendments 12, 17, 19, 20, 22 and 25 clarify the selection of the president and vice-president, outline Congressional terms, subject senators to popular voting, establish term limits for the president and detail the line of presidential succession.
The 21st amendment repeals the 18th amendment, which banned the manufacture and sale of alcohol. Amendments 23 and 26 give the District of Columbia representation in the Electoral College and establish the minimum voting age at 18, and the 27th amendment clarifies that a Congressional pay raise cannot take effect until the following term.