This study examines the efforts of the Union and Confederate diplomatic agents to influence the events along the Rio Grande during the Civil War. The paper compares the successful accomplishments of Confederate agent Jose Quintero to the hindered maneuverings of the Union representatives, Leonard Pierce and M. M. Kimuey. Utilizing microfilmed sources from State Department records and Confederate despatches, the paper relates the steps Quintero took to secure the Confederate-Mexico border trade, obtain favorable responses from the various ruling parties in northern Mexico, and hamper the Union agents' attempts to quell the border trade.

This paper provides a thematic approach to three major United States government document series relating to topics of early United States diplomatic relations with Mexico; treaty negotiations, the Santa 'Fe trade, the Texas question, and claims. The document series examined are .the United States presidential papers, United States Congressional documents , and the National Archives Record Group 59, diplomatic dispatches from United State Ministers to Mexico. Historians must make an evaluation of all: documentary evidence available for an accurate assessment of historical events. Inadequate analysis of these major United States document series has limited this necessary assessment in the area of United States Mexican diplomatic relations, 1821-1846.

This thesis contributes analyses of two works by Mexican composers: Rayo nocturnal (1989) by Victor Rasgado (b. 1959), and the Cuarteto da do (1988) by Juan Trigos (b. 1965). Although composed according to structuralist principles, a postmodern interpretation is offered. The analytical method applied is based on Allen Forte's set theory, including rhythmic and timbral dimensions that are integral to the conceptions of these works. A survey of modernism and postmodernism in twentieth-century Mexico serves to place these works in their cultural context.