Constitution

Article I, Section 9: Limits on Congress

Section 9 lists what Congress may never do: suspend habeas corpus outside rebellion or invasion, pass attainders or ex post facto laws, or spend without law.

4Conservative Editors · Published November 8, 2026

The text

The Migration or Importation of such Persons as any of the States now existing shall think proper to admit, shall not be prohibited by the Congress prior to the Year one thousand eight hundred and eight, but a Tax or duty may be imposed on such Importation, not exceeding ten dollars for each Person.

The Privilege of the Writ of Habeas Corpus shall not be suspended, unless when in Cases of Rebellion or Invasion the public Safety may require it.

No Bill of Attainder or ex post facto Law shall be passed.

No Capitation, or other direct, Tax shall be laid, unless in Proportion to the Census or enumeration herein before directed to be taken.

No Tax or Duty shall be laid on Articles exported from any State.

No Preference shall be given by any Regulation of Commerce or Revenue to the Ports of one State over those of another: nor shall Vessels bound to, or from, one State, be obliged to enter, clear, or pay Duties in another.

No Money shall be drawn from the Treasury, but in Consequence of Appropriations made by Law; and a regular Statement and Account of the Receipts and Expenditures of all public Money shall be published from time to time.

No Title of Nobility shall be granted by the United States: And no Person holding any Office of Profit or Trust under them, shall, without the Consent of the Congress, accept of any present, Emolument, Office, or Title, of any kind whatever, from any King, Prince, or foreign State.

Note: The fourth paragraph (Clause 4) was modified by the 16th amendment, which allows an income tax without apportionment. The first paragraph expired by its own terms in 1808.

In plain English

Section 9 is the original Constitution's short bill of rights against the federal government.

Clause 1: the slave trade. Congress could not ban the importation of enslaved people before 1808, though it could tax it. Congress banned the trade effective January 1, 1808, the first day it could.

Clause 2: habeas corpus. The "Great Writ" lets a prisoner demand that a court examine whether his detention is lawful. It may be suspended only in rebellion or invasion when public safety requires.

Clause 3: bills of attainder and ex post facto laws. Congress may not punish a named person or group by legislation without a trial, and may not make conduct criminal after the fact or increase the punishment for a past crime.

Clause 4: direct taxes. Head taxes and other "direct" taxes must be apportioned among the states by population.

Clauses 5 and 6: exports and ports. No tax on goods exported from any state, and no favoring one state's ports over another's.

Clause 7: the Appropriations Clause. No money leaves the Treasury unless Congress has appropriated it by law, and public accounts must be published.

Clause 8: titles and foreign emoluments. The United States may grant no title of nobility, and federal officers may not accept gifts, offices, titles or payments from foreign states without Congress's consent.

What the Founders said

Hamilton cited this section in Federalist No. 84 to answer the charge that the Constitution lacked a bill of rights. Protections against suspension of habeas corpus and against ex post facto laws and titles of nobility, he argued, were among the most important a constitution could contain. He called ex post facto punishment and arbitrary imprisonment "the favorite and most formidable instruments of tyranny."

Madison, in Federalist No. 44, wrote that "bills of attainder, ex post facto laws, and laws impairing the obligation of contracts, are contrary to the first principles of the social compact, and to every principle of sound legislation."

The Appropriations Clause made concrete the principle of Federalist No. 58: the power of the purse belongs to the people's representatives. The slave-trade clause, by contrast, was a concession to South Carolina and Georgia, defended in Federalist No. 42 as at least putting an end date on the trade.

How the courts have read it

  • Calder v. Bull (1798): the Ex Post Facto Clauses apply only to criminal laws.
  • Ex parte Milligan (1866): civilians could not be tried by military commission where civilian courts were open, even in wartime.
  • Pollock v. Farmers' Loan & Trust Co. (1895): a tax on income from property was a direct tax requiring apportionment; the 16th Amendment answered the decision.
  • United States v. Lovett (1946): a law cutting off the pay of three named federal employees was an unconstitutional bill of attainder.
  • OPM v. Richmond (1990): the government cannot be made to pay money Congress has not appropriated, even when an official misinformed a citizen.
  • United States v. IBM Corp. (1996): a tax on insurance premiums for exported goods violated the Export Clause.
  • Boumediene v. Bush (2008): detainees at Guantanamo Bay have the privilege of habeas corpus, and Congress had not provided an adequate substitute.
  • CFPB v. Community Financial Services Association (2024): a statute authorizing the bureau to draw funds from the Federal Reserve, up to a cap, satisfied the Appropriations Clause.

Why it matters now

Habeas corpus is the oldest liberty in the document and the one most tested in emergencies. Lincoln's suspension during the Civil War and the post-2001 detention cases show that the clause is never purely historical. A constitutionalist position holds the line in both directions: suspension is a power for Congress, in genuine rebellion or invasion, not a convenience for the executive.

The Appropriations Clause is Congress's strongest check on the other branches, and the one it most often neglects. Continuing resolutions, permanent appropriations, fees agencies keep for themselves, and funding outside the annual process all erode it. Congress keeps control of policy by keeping control of money.

The ban on bills of attainder carries a modern lesson. A legislature that singles out disfavored persons or groups for punishment, by name or by unmistakable description, is acting as a court. The Constitution forbids that combination of powers.

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