What was the effect of the north blockaded the southern ports ?

Blockade of the southern ports was an important war times strategy of the North during the Civil War.

Explanation:

Northern forces organized a blockade of Confederate ports to prevent cotton exports and war material from smuggling into the Confederacy. It was a significant economic strategy that effectively prevented Confederate access to arms that could be manufactured by the industrialized north itself. Despite the economic loss  Britain and France remained neutral and therefore the international concern was not an issue anymore in the war.