Common Interpretation

The Slave Trade Clause

Article 1, Section 9, Clause 1, is one of a handful of provisions in the original Constitution related to slavery, though it does not use the word “slave.” This Clause prohibited the federal government from limiting the importation of “persons” (understood at the time to mean primarily enslaved African persons) where the existing state governments saw fit to allow it, until some twenty years after the Constitution took effect. It was a compromise between Southern states, where slavery was pivotal to the economy, and states where the abolition of slavery had been accomplished or was contemplated. 

There is a sense in which the Clause is no longer constitutionally relevant since it expired in 1808. At the time the Constitution was adopted, there was no guarantee whether or when the federal Congress would act to prohibit the importation of slaves. So there is a legitimate inquiry about what took place in the political realm over the 20-year period between the adoption of the Constitution and 1808. During that time period, popular support for the abolition of the slave trade and slavery itself increased both in the United States and in other countries. There was more support for restricting the slave trade initially than slavery itself in this time period. In the 1790s, Congress passed statutes regulating the trade in slaves by U.S. ships on the high seas. The United Kingdom and other countries also passed legislation restricting the slave trade, increasing international pressure on the United States to likewise curb the practice.

In December 1806, President Thomas Jefferson’s annual message to Congress anticipated the upcoming expiration of Article 1, Section 9, Clause 1. His message said, “I congratulate you, fellow-citizens, on the approach of the period at which you may interpose your authority constitutionally to withdraw the citizens of the United States from all further participation in those violations of human rights which have been so long continued on the unoffending inhabitants of Africa, and which the morality, the reputation, and the best interests of our country have long been eager to proscribe.” Does it seem odd that a slave owner was supporting this legislation?

In 1807, the U.S. Congress passed a statute prohibiting the importation of slaves as of the first constitutionally-allowable moment of January 1, 1808. This act was signed by President Jefferson and entered into force in 1808, rendering this part of the Constitution irrelevant except as a historical curiosity. 

This in itself is a fascinating exception to constitutional change, in which a provision came with a built-in expiration date, after which the powers of the federal government would no longer be restricted. Note also that the Clause itself does not grant Congress the power to restrict the slave trade, but Congress presumably used the foreign and interstate commerce powers it had been given in Article 1, Section 8, to do so. 

In an important sense, there is a settled meaning of the Clause: it is no longer relevant in the same sense, for example, that the First Amendment is still constitutionally relevant. But the Clause, although constitutionally inoperative for over 200 years, still remains there for all to see and read. It is in the Constitution. And so the Clause, in a larger sense, has a continuing cultural and political constitutional relevance in the discourse of the morality and profitability of the international trade in human beings. People rightfully wonder today, and earlier, why is such a Clause there in the first place and to whom does it refer? We do know the Framers are talking about the slave trade, right? How attentive should we be to the specific language of the Clause or does the language actually inform us about what is trying to be conveyed? And why is this Clause the opening clause of Article 1, Section 9 of the Constitution?

Matters of Debate

The Invisible Past: Relics of Slavery in the Constitution

When the Constitution was drafted in 1787, slavery was a major component of the economy and society in the United States. It is odd that the Constitution does not use the word “slavery” in the provisions that most directly respond to the practice. It takes a careful reader to notice the “Importation of Persons Clause” in Article 1, Section 9, Clause 1, which does not mention exactly who are the persons who might be “imported.”

Likewise, the “Three-Fifths Clause” in Article 1, Section 2, Paragraph 3, provides that apportionment of representatives would be based on the population of free persons excluding “Indians not taxed” and “three fifths of all other persons.” Those “other persons” were, of course, the African slaves who made up around a third of the population of the Southern states at that time. The “Fugitive Slave Clause” in Article IV, Section 2, Clause 2, provides that “no person held to service or labour in one state, under the laws thereof, escaping into another, shall, in consequence of any law or regulation therein, be discharged from such service or labour, but shall be delivered up on claim of the party to whom such service or labour may be due.” Again, the text studiously avoids the use of the word slavery. Traces of a slave-holding society can be seen in other parts of the early Constitution, from the federal structure of the government including the Senate and limitations on the powers of the federal government, to the protection of property in the Due Process Clause of the Fifth Amendment.

Another Perspective

This essay is part of a discussion about the Slave Trade Clause with Gordon Lloyd, Robert and Katheryn Dockson Professor of Public Policy and Professor Emeritus, Pepperdine University. Read the full discussion here.

There was obviously deep tension between the practice of slavery and the notion in the Declaration of Independence that “all men are created equal, that they are endowed by their Creator with certain unalienable Rights.” Perhaps the drafters of the Constitution were too embarrassed to use the word “slavery.” Or perhaps, as other historians have argued, the drafters did not want to suggest that slavery was recognized under federal law, but rather existed only as a result of state laws. 

These constitutional provisions related to slavery reflected a compromise between Northern and Southern states that was essential to ratification of the Constitution and formation of the Union, but ultimately a compromise that was unsustainable, as shown finally by the Civil War. 

Political support for banning the slave trade came earlier and was more broadly shared than support for banning slavery itself. The practice of capturing and enslaving free persons in Africa and cruelly transporting them in crowded ships across the Atlantic was viewed by some at that time as more unjust than keeping generations of persons enslaved on plantations in the New World. Indeed, opposition to the slave trade was so strong that the constitution of the Confederacy in the Civil War even prohibited it. There was also international pressure to regulate the slave trade on the high seas, led by the United Kingdom and enforced through a network of international treaties prohibiting the slave trade.

In retrospect, slavery was a crack in the very foundation of the nation, which violently came apart in the constitutional crisis of the Civil War and was only sealed back together with Reconstruction and the Thirteenth, Fourteenth, and Fifteenth Amendments. We can still see the elements of these fissures in law and society today, in the legacy of persistent racial inequality. Just because you don’t mention something and call it by name does not mean it isn’t there.

Matters of Debate

Bona Libertas


Sections 4, 5, and 6, of Article VII of the Committee of Detail Report, August 6, 1787, restrained the 18 powers granted to Congress. Included in that list of powers was the power to regulate international commerce. Five delegates wrote this first draft of the Constitution: Nathaniel Gorham from Massachusetts, Edmund Randolph from Virginia, James Wilson from Pennsylvania, Oliver Ellsworth from Connecticut, and John Rutledge from South Carolina.                                                                     

Article VII, Sections 4, 5, and 6

Section 4. No tax or duty shall be laid by the Legislature on articles exported from any State; nor on the migration or importation of such persons as the several States shall think proper to admit; nor shall such migration or importation be prohibited.

Section 5. No capitation tax shall be laid, unless in proportion to the census herein before directed to be taken.

Section 6. No navigation act shall be passed without the assent of two-thirds of the members present in each House.

According to Section 4, what we now call the slave trade is completely 1) in the hands of each state and 2) out of the reach of Congress forever. Note that the word “slavery” is not mentioned.

The Three Sides

Three sides emerged in late August: principle, interest, and politics.

1. John Langdon “was strenuous for giving the power to the general government. He could not, with a good conscience, leave it with the States, who could then go on with the traffic.” John Dickinson, Luther Martin, George Mason, James Madison, Gouverneur Morris, James Wilson, and Edmund Randolph also opposed the slave trade on the grounds of principle. Martin argued that the slave trade was “inconsistent with the principles of the Revolution, and dishonorable to the American character, to have such a feature in the Constitution.” Mason stated that “every master of slaves is born a petty tyrant. They bring the judgment of Heaven on a country.”

Another Perspective

This essay is part of a discussion about the Slave Trade Clause with Jenny S. Martinez, Professor of Law and Warren Christopher Professor in the Practice of International Law and Diplomacy, Stanford Law School. Read the full discussion here.

2. Hugh Williamson, from North Carolina, reminded the delegates of political reality. “The Southern States could not be members of the Union, if the clause should be rejected.” He added: “both in opinion and practice he was against slavery; but thought it more in favor of humanity, from a view of all circumstances, to let in South Carolina and Georgia on those terms, than to exclude them from the Union.” Rutledge, chairman of the Committee of Detail, proclaimed: “Religion and humanity had nothing to do with this question. Interest alone is the governing principle with nations. The true question at present is, whether the Southern States shall or shall not be parties to the Union. . . . If the Convention thinks that North Carolina, South Carolina, and Georgia, will ever agree to the plan, unless their right to import slaves be untouched, the expectation is vain. The people of those States will never be such fools as to give up so important an interest.” Charles Pinckney agreed: “If slavery be wrong, it is justified by the example of all the world.”

3. Roger Sherman from Connecticut thought “it was better to let the Southern States import slaves than to part with them, if they made that a sine qua non.” He observed that the abolition of slavery seemed to be going on in the United States, and that the good sense of the several States would probably by degrees complete it. Mr. Ellsworth, also a member of the Committee of Detail, articulated the political position: the morality or wisdom of slavery are considerations belonging to the States themselves. Moreover, “slavery in time, will not be a speck in our country.” Massachusetts also sought accommodation. King said the whole “subject should be considered in a political light only.”

What is to be Done?

Mr. G. Morris “wished the whole subject to be committed, including the clauses relating to taxes on exports and to a navigation act. These things may form a bargain among the Northern and Southern States.”

The delegates appointed to a Committee of Eleven were Langdon, King, Johnson, Livingston, Clymer, Dickinson, L. Martin, Madison, Williamson, C.C. Pinckney, and Baldwin.

What sort of “bargain” would this Committee recommend? Langdon, King, Dickinson, Martin, and Madison opposed the Slave Clause provision on principle. Williamson, Pinckney, and Baldwin supported the Clause on the ground of interest. Perhaps Livingston, Johnson, and Clymer could help create an accommodation.

Governor Livingston from the Committee delivered the Report:

“Strike out so much of the fourth Section as was referred to the Committee, and insert, ‘The migration or importation of such persons as the several States, now existing, shall think proper to admit, shall not be prohibited by the Legislature prior to the year 1800; but a tax or duty may be imposed on such migration or importation, at a rate not exceeding the average of the duties laid on imports.’ The fifth section to remain as in the Report. The sixth Section to be stricken out. . . . ”


The Committee permitted Congress to regulate the slave trade after 1800 and impose a tax on such importation. Moreover, the Clause was confined to “the several states, now existing” that considered it “proper.” Congress was free to regulate the slave trade in the territories and impose restrictions on new states that entered the Union.

General Pinckney moved to strike out the words, “the year eighteen hundred,” and to insert the words “the year eighteen hundred and eight.” It passed 7-4.

The delegates had moved a long way from never permitting Congress to regulate the slave trade to permitting Congress to regulate the trade after 1808. Madison considered 1800—the birth of a new century—to be the more principled compromise.  New Jersey, Pennsylvania, Delaware, and Virginia voted “no.” They wanted 1800 instead of 1808. 

Thus Article 1, Section 9 of the Constitution: “The migration or importation of such persons as the several states now existing shall think proper to admit, shall not be prohibited by the legislature prior to the year 1808.” 

Matters of Debate

More about Article I

The Drafting Table

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