U.S. Supreme Court
The Julia, 12 U.S. 8 Cranch 181 181 (1814)
12 U.S. (8 Cranch) 181
The sailing on a voyage under the license and passport of protection of the enemy in furtherance of his views or interests constitutes such an act of illegality as subjects the ship and cargo to confiscation as prize of war.
Strictly speaking, in war all intercourse between the subjects and citizens of the belligerent countries is illegal unless sanctioned by the authority of the government or in the exercise of the rights of humanity. chanrobles.com-red