Prize Cases

Prize Cases (1863) – 67 U.S. 635  – was a case argued before the Supreme Court of the United States in 1862 during the American Civil War. The Supreme Court's decision declared constitutional the blockade of the Southern ports ordered by President Abraham Lincoln. The opinion in the case was written by Supreme Court Justice Robert Cooper Grier.

Background
Facing the secession of several states from the Union and the possibility of open hostilities, Abraham Lincoln did not ask Congress to declare war on the Confederate States of America as he believed this would be tantamount to recognizing the Confederacy as a nation. Instead, Lincoln instituted a naval blockade which had interesting legal ramifications because nations do not blockade their own ports; rather  they close them. By ordering a blockade, Lincoln essentially declared the Confederacy to be belligerents instead of insurrectionists.

The Confederate States were mostly agrarian, and almost all of their machined and manufactured goods were imported. At the beginning of the war there was only one significant steel mill and manufactory in the South, the Tredegar Iron Works in Richmond, Virginia. Moreover, the southern economy depended on the export of cotton, tobacco and other crops. The blockade of the South resulted in the capture of dozens of American and foreign ships, both those attempting to run the highly efficient blockade and smuggle goods and munitions to the South as well as those attempting to smuggle exports from the South.

Decision
The question before the court dealt with the seized ships. In admiralty, a ship captured during war may be kept as a prize. If there was no formal war, then capturing ships and impounding them is piracy. The Court looked to international law, and concluded that "it is not necessary to constitute war, that both parties should be acknowledged as independent nations or sovereign States." The Court further stated that the President, as commander-in-chief of the armed forces, had the authority to proclaim a blockade as a method of waging war. The Court noted that Congress, in 1861, had adopted a law ratifying and approving the President's proclamation as well as other actions taken to prosecute the war, but did not declare whether such Congressional approval was necessary to legitimize the blockade.

Dissent by Justice Nelson
The dissenting opinion by the Court acknowledges that the President is not provided the authority to declare war. The power to declare war lies with Congress. The Civil War did not exist until it was declared so by Congress. Lincoln ordered the blockade before Congress had declared a war. As such, Nelson and the minority believed that the blockade was unconstitutional. They further contend that even had Lincoln been granted the authority for the blockade, he would need to provide the neutral parties with a proper notice of seizure.

Conclusion
The Supreme Court found the actions of President Lincoln constitutional.