Did the blockade work and why did they have a blockade?

shutting off a part or region to prevent passage by hostile forces

A blockade is any effort to prevent supplies, troops, information or aid from reaching an opposing force. Blockades are the cornerstone to nearly all military campaigns and the tool of choice for...

prevent from sending or receiving goods

{| |- | Blockades are often very effective. The German attempt to blockade England through a curtain of U-Boats had some major affects on the Allied efforts. It was unsuccessful in preventing goods...

by using ironclads and over powering woodenships. Or they would use a ship to destrack union ships and others would sneak in.