In May 1917, the United States Navy dispatched a South Atlantic patrol squadron to Brazil under the command of Admiral William B. Caperton, Commander-in-Chief of the Pacific Fleet. Caperton, who soon saw his mission as more diplomatic than military, became the United States' best-known representative in South America and worked closely with civilian diplomats to maximize United States influence in the area. His two-year tour of duty from 1917 to 1919, therefore, constitutes a little-known case study in the attempted use of naval forces for diplomatic purposes, and in the development of some aspects of United States policy in South America.