One of Lincoln's military strategies was to blockade the South's ports and approximately of shoreline. At the start of the war, with only a few ships, this was all but impossible. By war's end, the Union had captured or destroyed 1500 blockade runners. But with nearly 5 out of 6 shops able to evade the blockade, Great Britain argued it was not recognized by international law as it was a "paper blockade." The Confederacy was able to ship only a small part of its main cash crop, cotton, to England during the war. Three years before the war the South had shipped 10 million bales of cotton a year. During the war they shipped a total of only 500,000 bales. But English manufacturers had stockpiled large quantities of Southern cotton from the huge exports before the war. What they had on hand carried them through most of the war.