Schooner Exchange v. McFaddon
The Supreme Court ruled that a warship belonging to a foreign nation, visiting an American port peacefully, cannot be seized or sued over in American courts, because letting it dock there carried an unspoken promise that the United States would not interfere with it.
This decision, written by Chief Justice Marshall, became the foundation of the American law of sovereign immunity, establishing that a country's own courts generally cannot exercise power over the property and armed forces of a friendly foreign government.
How it got here: The District Court dismissed the men's claim to the ship, but the Circuit Court reversed that dismissal, and the case reached the Supreme Court.
The Case in Depth
What happened
Two men claimed they had once owned a ship called the Exchange, which they said had been unlawfully taken from them. By the time the ship arrived in an American port, it was no longer a private vessel — it had become an armed warship commissioned by the Emperor of France. The original owners sued in American court to reclaim the vessel, and the case tested whether they could do so.
The question before the Court
Could a man who once owned a ship sue to reclaim it in an American court after it became an armed warship of a foreign emperor?
Why it matters
The ruling meant that foreign warships, and by extension other government property, could visit or pass through American ports without fear of being seized by private lawsuits, encouraging peaceful international travel and diplomacy. It also gave American courts a lasting framework for deciding when foreign governments and their property are off-limits to domestic legal claims.
What changes now
The Supreme Court's ruling was final on the merits: the Circuit Court's decision reinstating the claim was reversed, and the District Court's original dismissal of the case was reinstated. The former owners had no further avenue in American courts to reclaim the ship. The decision set a lasting precedent that would guide how American courts treat the property and armed forces of foreign governments for generations afterward.
What this does not decide
The Court explicitly declined to decide whether a foreign sovereign's private property, as opposed to his warships or military forces, would enjoy the same immunity from local courts, and left open how far immunity might extend to private vessels entering under treaty protections during distress.
How the Court got there
The legal reasoning, step by step
- The Court started from the principle that a nation's jurisdiction over its own territory is complete and exclusive, so any exception to that jurisdiction must trace back to the nation's own consent, whether expressed outright or implied from custom and circumstance.
- The Court walked through recognized categories where nations have implicitly given up part of their territorial power over visitors, including the immunity of visiting sovereigns, the immunity of foreign ambassadors, and the immunity of foreign armies granted passage — in each case because the host nation could not reasonably be understood to intend subjecting a foreign power's dignity and forces to its own courts.
- Extending this reasoning to ships of war, the Court held that when a friendly nation's port is open to foreign warships without any special prohibition, the vessel's entry is understood to carry an implied promise that the visiting country's armed vessel remains free from the host nation's jurisdiction, so long as it behaves peacefully.
- The Court distinguished this from ordinary private citizens and merchant ships, which owe temporary obedience to local law when they enter another country for business or travel, because unlike a warship they do not act as an extension of a foreign sovereign's power and dignity.
- Applying this framework, the Court found that the Exchange, now a commissioned French warship, had entered an American port under the ordinary implied license extended to warships of a friendly power, so it fell outside the reach of American courts even though it may once have belonged to the men who sued.