The union blockade during the civil war?

The union blocked southern access to the sea preventing it from getting resources from outside the area.

The union blockage during the civil war took place at southern united states, Atlantic ocean and Gulf of mexico

Explanation:

The main aim of the blockage during the civil war was to prevent the export of cotton and the smuggling of weapons. it took place at confederate ports and it was carried out by over 500 naval ships patrolling the south