Colonel David D. Barrett led the American Observation Group to Yanan to investigate the military and political power of the Chinese Communist Party to determine if the U.S. should establish official relations. The trip, known as the Dixie Mission, took place between July 1944 until March 1947.
Source of Descriptive Information
Alexander, B. (1992). The triumph of China: The middle kingdom's long march from degradation to world power in the twentieth century. Farrar, Straus & Giroux. Available at http://bevinalexander.com/china/27-dixie-mission.htm