Leslie B. Rout, Jr. (1935–1987) was not only a historian, teaching for many years at Michigan State University, but also a jazz musician. He became interested in the Chaco War and its subsequent settlement while traveling in Latin America as a member of a United States government-sponsored musical group. Informed that unpublished documents could be made available, Rout returned to Brazil, Argentina, Uruguay, and Bolivia in 1965 to prepare this study.