This investigation resulted from a pilot research paper prepared in conjunction with a graduate course on the Civil War. This study suggested that the Federal blockade of the Confederacy may not have contributed significantly to its defeat. Traditionally, historians had assumed that the Union's Anaconda Plan had effectively strangled the Confederacy. Recent studies which compared the statistics of ships captured to successful infractions of the blockade had somewhat revised these views. While accepting these revisionist findings as broadly valid, this investigation strove to determine specifically the effectiveness of Admiral Farragut's West Gulf Blockading Squadron. Since the British Foreign Office maintained consulates in three blockaded southern ports and in many Caribbean ports through which blockade running was conducted, these consular records were vital for this study. Personal research in Great Britain's Public Record Office disclosed valuable consular reports pertaining to the effectiveness of the Federal blockade. American consular records, found in the National Archives in Washington, D.C. provided excellent comparative reports from those same Gulf ports. Official Confederate reports, contained in the National Archives, various state archives and in the published Official Records of the Union and Confederate Armies revealed valuable statistical data on foreign imports. Limited use was made of Spanish and French consular records written from ports involved in blockade running. Extensive use was made of Senate and House documents in determining Federal blockade policy during the war. The record of the Navy's enforcement of the blockade was found in The Official Records of the Union and Confederate Navies. The contemporary reports of Union and Confederate governmental officials was found in James D. Richardson's respective works on The Messages and Papers, and in the published diaries of Gideon Welles and Gustavas Fox. Contemporary newspapers and first hand accounts by participants on both sides provided color and perspective. In evaluating the performance of the West Gulf Blockading Squadron, a review of the international laws governing blockading was undertaken, emphasizing America's traditional posture regarding the blockades of other nations. Under Gideon Welles, the Federal navy became a powerful and efficient force, although the navy's enforcement of the blockade often resulted in serious diplomatic embarrassment, especially from maritime incidents occurring near the mouth of the Rio Grande River. Nearby Matamoros, Mexico virtually became an international trade mart for Confederate cotton and imports. However, much contraband trade was conducted through blockaded Gulf ports such as Galveston, Texas. It is concluded that the West Gulf Blockading Squadron performed only satisfactorily at best. This did not result so much from innate limitations as from outside factors. Among the latter were the open door at Matamoros, the Lincoln administration's diplomatic timerity and national policies that authorized a type of cotton trade with the south. Further, the better vessels were assigned land campaign priorities. The statistics of the cotton trade in this portion of the Confederacy show that cotton exports were significantly high. Most of these exports egressed via Matamoros, but a high percentage existed through blockaded Gulf ports. The fact that 10,000 bales of cotton left the heavily guarded port of Galveston in the last six months of the war indicates the inefficiency of the West Gulf Blockade. It appears that the West Gulf Blockade was effective enough to create scarcity but never effective enough to seriously interdict the flow of trade. That the Trans-Mississippi Confederacy was largely sustained by imports underscores the blockade's limited effectiveness.