Did the Naval Blockade Help or Hurt the Union?

Since this is a question I was sort of pondering, I wanted to see what everyone else thinks.

At the start of the Civil War, Abraham Lincoln proclaimed a naval blockade of the Confederacy. This almost immediately proved to be a mistake, because it recognized the Confederacy as an independent nation. Naval blockades are only carried out against foreign powers, and ports within the country are simply shut down by the government. By blockading, Lincoln was admitting that he had no authority over Southern ports. The South immediately jumped on this, and sought help from European powers.

England, as an experienced maritime superpower, was hesitant to get involved. They feared that the situation could be binding, and they didn't want such hostile relations with the Union. No formal alliances were made, but a system of "blockade runners" was set up. First, cargo ships came from Europe to rendezvous points in the West Indies (often the port of Nassau). From there, the precious cargo would be transferred to the Confederate blockade runners, which were small, light and swift. These crafts would attempt to slip past the blockade and bring much needed supplies to the Southerners. About eighty percent of the time, they were stopped. However, successfully blockade running was considered highly admirable, and captains were glorified for making only one or two trips.

The blockade was put in place to cease the export of cotton and the import of weapons, going to and from Europe. The force that the Union scrapped together to execute this job was an eclectic mix, including everything from gunships to steam boats to skimmers. Such a mix made the Union seem disorganized, but in reality, it granted them the ability to pursue ships of any kind. Thus, their forces were more versatile, and they were fairly effective in stopping the Southern blockade runners.

After a while, it became clear that the South did not have enough self-sufficiency to survive. They had overestimated the lengths that European powers would go to to acquire cotton. France and England, in fact, were well stocked on cotton, for in the previous few years, they had received an ample supply from the South. "King Cotton" was finally failing on the Southerners. They also did not possess the manufacturing power of the North. This meant that, not only could they not grow their own food, but they also could not make their own weapons. As a result, the Southern economy began to slowly run dry.

So the Union had recognized Southern independence, but the South had proven that, although they could try for independence, they could never be self-sufficient. This was a glaring weakness for the South, particularly as their need for supplies grew more and more dire. What had initially looked like a fumble for the Union ended up battering the Southern economy. One could stop there, and say that it helped the Union, but there is one more important factor to consider...

The South's desperate need for naval defense sparked the inspiration for the Merrimac. The Merrimac was originally a vessel owned by the North, but it was not put into combat. When the South took a Northern shipyard, they gained over a thousand cannon, along with the Merrimac. After lots of innovation, the Southerners turned the this old ship into a threatening giant. It moved extremely slowly, but was so well equipped that, at one point, it easily took out two Federal navy ships with only minor damage to itself. The significance of the Merrimac is that it came as a direct result of the blockade, for it was created to defend Southern waters.

In the end, the Union was able to build far more ships than the South due to their superior manufacturing abilities. The Confederacy ended up burning the ship themselves for fear that the Union would use it, so the Union undoubtedly won this battle. However, the question still remains whether or not it was worth it for the Union to carry out a blockade. The Merrimac caused an uproar of panic in the North, and it certainly caused significant harm to the Union. The blockade itself was a success, but it directly resulted in a disaster. All things considered, one can easily say that it the blockade as a whole did benefit the North due to  the North's naval strength, which both carried out the blockade and quelled the Merrimac.