The New Student's Reference Work/Blockade

Blockade, in naval warfare is the shutting up of a port of a country, cutting off communication with the outside world. It is effected by stationing sufficient numbers of ships off the ports to make entrance impracticable. Neutral powers, because the interference with their commerce injures them, must be fully notified of the blockade by the state that attempts it. Then endeavors to deal with the ports blockaded become contrary to the law of nations, and attempts to trade with such ports render ships and cargoes liable to confiscation. But if blockades are to be binding on neutrals, they must not merely be blockades on paper or blockades by proclamation. They must also be physically effective. Among famous blockades are that of the European coast from Denmark to Italy in 1807-8, when Napoleon was fighting England; the Crimea in 1854-6 by England, France and Sardinia; the coast of the Confederate States by the Federal Government during 1861-5; Cuba by America in 1898; and Venezuela by Britain, Germany and Italy in 1903.