On July 10, 1861, a Union warship overtook a merchant brig called the Amy Warwick off Cape Henry, Virginia. The brig was sailing under American colors with 5,100 bags of coffee from Rio de Janeiro, and, according to the record, her captain did not know the country was at war. The navy took the ship and cargo anyway, and a federal court in Massachusetts condemned both as enemy property because the owners lived in Richmond. The owners appealed on a question that sounds simple. Who gave the President the power to do this? The Constitution assigns the power to declare war to Congress, and Congress had declared nothing.
How did a naval blockade reach the Supreme Court?
After the attack on Fort Sumter, President Lincoln proclaimed a blockade of Southern ports in April 1861. A blockade is a naval closure of an enemy coast, enforced by capturing ships that try to get through. Congress was not in session. It did not convene until an extraordinary session opened on July 4, 1861.
Ships taken before Congress acted went to prize courts, which decide whether a captured vessel and its cargo may be kept as “prize” by the captors. Those courts condemned the Amy Warwick and several other vessels, including a British barque and a Mexican schooner. The owners argued that a blockade is a right of nations at war, that only Congress can put the nation at war, and that the captures were therefore void.
What did the Court decide about the President’s war power?
In The Prize Cases, 67 U.S. (2 Black) 635 (1863), the Court ruled 5 to 4 that the blockade was lawful. Justice Grier wrote for the majority. He began by agreeing with the owners on one point: the Constitution gives Congress alone the power to declare a national or foreign war, and the President has no power to initiate a war against a foreign nation or a state.
Then the majority drew a distinction. When a foreign nation invades, the President is “not only authorized but bound to resist force by force.” Id. at 668. He does not start the war by accepting the challenge. A civil war, the Court added, is never solemnly declared. It becomes a war through its accidents, meaning the number, power, and organization of the people who wage it. This rebellion had “sprung forth suddenly from the parent brain, a Minerva in the full panoply of war,” and the President had to meet it in the form it took, without waiting for Congress to give it a name. Id. at 669.
The Court leaned on two further supports. Britain had issued a proclamation of neutrality on May 13, 1861, which treated both sides as belligerents. And Congress passed a statute later in 1861 approving the President’s acts as though he had acted under prior authority. The Court said that if authority had been needed, the approval cured the defect. The Court also held, on a second question, that property of people living in the enemy’s territory could be captured as enemy property whatever their personal loyalty.
Who decides that a war exists?
The hard part is who decides. The majority said the President must determine whether he faces a war, and must decide what degree of force the crisis demands. It added that his proclamation of blockade is itself conclusive evidence that a state of war existed. Read alone, that sentence is circular: the power to respond to war depends on a war existing, and the evidence offered is the President’s own act. The other supports, foreign recognition and later congressional approval, keep the holding from resting on that sentence alone. But the deference standard is the part that travels to other cases.
Justice Nelson, dissenting, saw a different problem. Until Congress acts, he wrote, a rebellion is a matter for the President’s power to execute the laws and call out the militia, and that power operates against individuals. A blockade under the law of nations operates against a whole territory and turns every resident into an enemy. In his view the President had no power to make that change, and Congress could be assembled within thirty days. Three justices, including the Chief Justice, joined him. The majority prevailed by one vote.
Why does the line between defending and declaring still matter?
The case marks where presidential power starts and where it stops. A President may answer an attack on his own authority, and courts will not require him to wait. But the opinion says in plain terms that he cannot initiate a war, and it treats Congress’s later approval as insurance instead of as a formality. That sequence, action first and legislative endorsement after, is the one the Court approved here.
What the case does not supply is a measure of duration or scale. Nothing in the opinion says how long a response may run, or how large, before it requires Congress’s authorization.
Related: Can the government hold a citizen without a trial? applies the same war power to a citizen captured abroad and held at home, and Why is the most famous part of this case not what decided it? covers Youngstown. More Con Law posts are collected in Law School Notes.
I am a law student, not a lawyer. Nothing here is legal advice.
