The President declared a blockade in April of 1861 during the Civil War.
Could the President instituted a blockade of ports in possession of persons in armed rebellion against the government?
Was the property of the people domiciled or residing in those states a proper subject of capture on the sea as “enemy” property?
Yes, the President could institute a blockade of ports in possession of persons in armed rebellion against the governmenta
Justice Nelson argued that domestic law, not the law of nations that should govern the use of the war power here, and that the acts of Congress referred to by the Supreme Court’s opinion did not cover the President’s actions here. According to Justice Nelson, only Congress can determine whether war exists, and no citizen can be punished until then unless they personally violated the law.
According to the Supreme Court, for there to be war for the purposes of the president’s war power, it is not necessary that both parties are acknowledged as independent nations. One party claiming independence from the other is sufficient to establish war for war power purposes. Additionally, while Congress has the power to declare war, Congress passed laws granting the president the authority to use military and naval forces to suppress insurrection and invasion. Additionally, as commander-in-chief, the President had the discretion to determine if suppressing the insurrection and civil war warranted a blockade. The existence of a war is not dependent on legislative sanction.
The Supreme Court rejected the argument that only citizens of foreign nations could be “enemies” for the purpose of capturing enemies’ property during war. It did not matter if the citizens whose property was captured were loyal to the United States. The produce from the land of the hostile power and the property engaged in the hostile power’s commerce are legitimate captures.