Constitution of the United States

The Constitution of the United States is the world's oldest written national constitution still in force, drafted at the Philadelphia Convention between May and September 1787 and signed on 17 September 1787 by delegates including James Madison, often called its "Father," Alexander Hamilton, and Benjamin Franklin. It superseded the Articles of Confederation (1781), whose weak central government had proven unworkable. The document was ratified after the Federalist–Anti-Federalist debate, captured in The Federalist Papers (1787–88) by Hamilton, Madison, and John Jay, and came into effect on 4 March 1789. Its Preamble ("We the People") asserts popular sovereignty as the source of constitutional authority.

Structurally, the Constitution comprises a Preamble and seven Articles. Article I vests legislative power in a bicameral Congress (Senate and House of Representatives); Article II vests executive power in the President; Article III establishes the Supreme Court and the federal judiciary. Article IV governs inter-state relations (full faith and credit, privileges and immunities); Article V prescribes the amendment process; Article VI contains the Supremacy Clause; and Article VII set the ratification threshold at nine of thirteen states. The framework embeds separation of powers and checks and balances — the President's veto, the Senate's advice and consent on treaties and appointments, and judicial review, the last established not by text but by Marbury v. Madison (1803). Federalism divides sovereignty between the Union and the states, with residuary powers reserved to states under the Tenth Amendment.

The Constitution has been amended only 27 times. The first ten amendments — the Bill of Rights (1791) — guarantee free speech, due process, and protection against unreasonable searches. The Reconstruction Amendments followed the Civil War: the Thirteenth (1865) abolished slavery, the Fourteenth (1868) guaranteed equal protection and due process, and the Fifteenth (1870) secured voting rights regardless of race. Landmark interpretations include Brown v. Board of Education (1954) on segregation, Roe v. Wade (1973, overruled by Dobbs v. Jackson, 2022), and Obergefell v. Hodges (2015) on marriage equality. Article V's rigid amendment route — two-thirds of both Houses and three-quarters of states — makes it among the most difficult constitutions to amend, a deliberate contrast to the flexibility studied in comparative polity.

For the exam, the US Constitution is a staple of UPSC's comparative constitution segment in Indian Polity (GS Paper II) and World History (GS Paper I), and of FSOT's American government component. Candidates must distinguish it from the Indian Constitution: the US has a rigid, brief document with a presidential system and clear separation of powers, whereas India adopted parliamentary government and a fluid amendment procedure under Article 368. Questions frequently compare Marbury v. Madison-style judicial review with the Indian "basic structure" doctrine of Kesavananda Bharati (1973), contrast "due process of law" with India's "procedure established by law" (read into Article 21 via Maneka Gandhi, 1978), and probe how the Bill of Rights influenced India's Fundamental Rights. Knowing the seven Articles, the 27 amendments, and the federalism–separation-of-powers architecture is essential.