The Confederate States of America (1861–1865) started with an agrarian-based economy that relied heavily on slave-worked plantations for the production of cotton for export to Europe and to the northern US. If classed as an independent country, the area of the Confederate States would have ranked as the fourth-richest country of the world in 1860. But, when the Union began its blockade of Confederate ports in the summer of 1861, exports of cotton fell 95 percent and the South had to restructure itself to emphasize the production of food and munitions for internal use. After losing control of its main rivers and ports, the Confederacy had to depend for transport on a delicate railroad system that, with few repairs being made, no new equipment, and destructive raids, crumbled away. The financial infrastructure collapsed during the war as inflation destroyed banks and forced a move toward a barter economy for civilians. The Confederate government seized needed supplies and livestock (paying with certificates that were promised to be paid off after the war, but never were). By 1865, the Confederate economy was in ruins. Agriculture The main prewar agricultural products of the Confederate States were cotton, tobacco, and sugarcane, with hogs, cattle, grain and vegetable plots. Pre-war agricultural production estimated for the Southern states is as follows (Union states in parentheses for comparison): 1.7 million horses (3.4 million), 800,000 mules (100,000), 2.7 million dairy cows (5 million), 5 million sheep (14 million), 7 million cattle (5.4 million), 15.5 million swine (11.3 million), 187 million pounds of rice, 199 million pounds of tobacco (58 million), 5 million bales of cotton, 20 million bushels of oats (138 million bushels), 31 million bushels of wheat (114 million bushels), and 280 million bushels of corn (396 million bushels). In 1862, there was a severe drought that, despite efforts to switch from cotton planting to grain farming, caused food shortages and even bread riots in 1863–64. The harvests were fairly abundant after 1862, but often went to waste as they could not be harvested or moved to markets. Corn was raised in large quantities, and, in general, the raising of food products instead of tobacco and cotton was a necessity. The scarcity of food in the armies and cities was due mostly to the shortage of male labor, the disruption of transportation and finance. Compounding the problem was the ever-increasing number of refugees flooding into cities; food