The correct answer is they brought needed supplies into the state. Various nations employ the old naval tactic of blockading with the intention to starve, outlast, or destroy their enemies. The main objective of blockades is to prevent ships from delivering support, supplies, goods or food to enemy ports.
In 1861, the Union blockade was carried out to stop Southern commerce and damage the Confederacy during the Civil War. To counter these efforts, Confederate blockade runners took care of bringing as many supplies as needed to the struggling Confederacy.