Union Blockade

The Union blockade took place between 1861 and 1865, during the American Civil War, when the Union Navy maintained a strenuous effort on the Atlantic and Gulf Coast of the Confederate States of America designed to prevent the passage of trade goods, supplies, and arms to and from the Confederacy. Ships that tried to evade the blockade, known as blockade runners, were mostly newly built, high-speed ships with small cargo capacity. They were operated by the British (using Royal Navy officers on leave) and ran between Confederate-controlled ports and the neutral ports of Havana, Cuba; Nassau, Bahamas, and Bermuda, where British suppliers had set up supply bases.

President Abraham Lincoln proclaimed the blockade on April 19, 1861. His strategy, part of General Winfield Scott's Anaconda Plan, required the closure of 3,500 miles (5,600 km) of Confederate coastline and twelve major ports, including New Orleans, Louisiana, and Mobile, Alabama, the top two cotton-exporting ports prior to the outbreak of the war, as well as the Atlantic ports of Richmond, Virginia, Charleston, South Carolina, Savannah, Georgia, and Wilmington, North Carolina. To this end, the Union commissioned 500 ships, which destroyed or captured about 1,500 blockade runners over the course of the war; nonetheless, five out of six attempts to evade the blockade were successful. However the blockade runners carried only a small fraction of the usual cargo.