Import-Export Clause

Doctrine

Brown v. Maryland gave the Clause its classic early scope, holding that a state license tax on importers was effectively a duty on imports. The original-package doctrine later limited state taxation while goods remained imports.

Story's Commentaries reprint Marshall's Brown opinion at length, including the doctrine's founding statement, in Marshall's own words. An import loses its distinct character and becomes taxable once it is mixed into the general property of the state; until then, a tax on it is a tax on the import itself:

"[W]hen the importer has so acted upon the thing imported, that it has become incorporated and mixed up with the mass of property in the country, it has, perhaps, lost its distinctive character, as an import, and has become subject to the taxing power of the state. But, while remaining the property of the importer, in his warehouse, in the original form or package, in which it was imported, a tax upon it is too plainly a duty on imports to escape the prohibition in the constitution." — Chief Justice Marshall, Brown v. Maryland, quoted in Joseph Story, Commentaries on the Constitution § 1021 (1833)

Marshall's practical argument for reading "duty on imports" to reach the article, not merely the moment of importation, rests on the functional identity between taxing a sale and taxing the entry of goods:

"There is no difference, in effect, between a power to prohibit the sale of an article, and a power to prohibit its introduction into the country. The one would be a necessary consequence of the other. No goods would be imported, if none could be sold." — Chief Justice Marshall, Brown v. Maryland, quoted in Joseph Story, Commentaries on the Constitution § 1018 (1833)

Modern doctrine shifted in Michelin Tire Corp. v. Wages, which upheld a nondiscriminatory ad valorem property tax on imported goods stored in a warehouse. The Court focused on the Clause's purposes: preserving federal revenue, preventing state interference with foreign commerce, and preventing coastal states from taxing inland consumers through import duties. Department of Revenue v. Association of Washington Stevedoring Cos. extended that approach to some service charges connected to imports and exports.

The Clause applies to foreign imports and exports, not interstate trade. It also does not reach every fee or charge. The key questions are whether the item remains an import or export, whether the charge is an impost or duty, and whether the charge fits the inspection-law exception.

Originalist note

The Clause protects national control over foreign commerce and prevents port states from exploiting their geographic position. The Convention record shows the prohibition tightening in stages: Madison's 28 Aug. 1787 motion made the ban on state imposts and duties on imports absolute rather than merely licensable by Congress, and King's follow-on motion extended the ban to exports by a bare 6-5 vote. The inspection-law exception now in the text was not part of the original design — it entered on Mason's motion of 12 Sept. 1787, after he warned that an absolute ban would ruin the "Staple States" by denying them a way to recover the cost of inspecting, packing, and storing produce before export:

"provided nothing herein contained shall be construed to restrain any State from laying duties upon exports for the sole purpose of defraying the Charges of inspecting, packing, storing and indemnifying the losses, in keeping the commodities in the care of public officers, before exportation." — Records of the Federal Convention, Madison's Notes, 12 Sept. 1787

Hamilton's Federalist No. 32 supplies the founding-era gloss on how the prohibition interacts with the states' residual taxing power, reading it as a "negative pregnant":

"The restriction in question amounts to what lawyers call a NEGATIVE PREGNANT; that is a negation of one thing and an affirmance of another; a negation of the authority of the States to impose taxes on imports and exports, and an affirmance of their authority to impose them on all other articles." — Federalist No. 32

Story's Commentaries (§ 1013) confirms the drafting sequence and frames the Clause as preventing a "petty warfare of regulation" among the states. Modern doctrine is less formal than Brown's original-package rule but still tracks the founding purposes by targeting discriminatory or revenue-raising state charges on foreign trade.

Virginia Convention, 15 June 1788: does the "net produce" rule reach Virginia's tobacco-inspection system?

Mason's 12 Sept. 1787 Convention-floor exception for inspection-law costs (above) got its first ratification-era stress test on the Virginia convention floor, applied to the state's own forty-year-old tobacco-inspection duties. George Mason objected that the clause's "net produce... shall be for the use of the treasury of the United States" language would strip Virginia of the ability to cover its own inspection losses — a burnt tobacco warehouse, for instance — even though the underlying duty exists only to fund inspection in the first place:

"For forty years we have laid duties on tobacco, to defray the expenses of the inspection, and to raise an incidental revenue for the state... But if any tobacco-house is burnt, we cannot make up the loss. I conceive this to be unjust and unreasonable... This is one of the most wanton powers of the general government." — George Mason, Virginia Convention, 15 June 1788

George Nicholas answered by separating two things Mason's objection treats as one: the clause's "revision and control" reaches laws imposing duties on tobacco exports, not laws regulating the inspection process itself, and a state may draft the two as separate statutes so that inspection-loss compensation never touches the "net produce" line at all:

"It does not follow that laws made for the regulation of the inspection shall be subject to the revision of Congress... for the duties on exports might be in one law, and the regulation of the inspection in another. The states may easily make them separately... A tax may be laid to make up this loss." — George Nicholas, Virginia Convention, 15 June 1788

Mason replied that the two could not in practice be kept apart — "the regulation of the inspection, and the imposition of duties, must be inseparably blended together." James Madison closed the exchange with the Clause's structural rationale rather than its administrative detail: the rule protects states whose exports pass through another state's ports (Virginia exporting North Carolina's produce, Pennsylvania exporting New Jersey's and Delaware's) from a hosting state taxing a neighbor's goods for its own exclusive benefit, and he read the clause's final phrase verbatim to confirm Nicholas's separate-statute answer:

"[I]t only says that 'the net produce of all duties and imposts, laid by any state on imports or exports, shall be for the use of the treasury of the United States,' which necessarily implies that all contingent charges shall have been previously paid." — James Madison, Virginia Convention, 15 June 1788

key-insight

Nicholas's and Madison's answer to Mason turns on a drafting distinction — duty-law and inspection-law as two separate statutes — that the constitutional text itself does not require and that the Convention floor never tested against an actual state statute. The exchange is the wiki's first ratification-era floor application of the inspection-law exception Mason himself had won at Philadelphia (above), and it is Mason, the exception's own author, who argues on the Virginia floor that it will not work as drafted.