20. The risks of blockade running increased as the war went on
In 1861 and 1862, the chance of a blockade runner being captured on the run to the British ports and back was about 1 in 9. By the end of 1863, it was about 1 in 3. By war’s end, the odds were fifty-fifty, and the practice had all but been suppressed. There were several reasons for the once-lucrative practice being brought to the end. One was the increase in the size of the Union Navy. The Navy retained many of the blockade runners it captured, and unconcerned with carrying cargo, armed them. This gave the Navy ships of equal speed to their quarry, and superior firepower. The Navy also gained experience in monitoring the routes taken by the blockade runners.
The single greatest factor was the reduction of usable ports. Savannah was lost in the opening months of 1862, when Fort Pulaski was taken, effectively closing the port. New Orleans was easily sealed early in the war, and captured in April, 1862. Only three major ports were available east of the Mississippi River as 1863 began – Mobile, Charleston, and Wilmington. A greater number of suitable ships to guard a decreasing number of ports foreordained the results. After 1863 about half of the British investors in the business withdrew with their profits. The remainder reinvested theirs until the end of the war, an act which lost them considerable sums of money.