The purpose of this dissertation is to analyze the six special military units which were authorized and created by the War Department under the direction of Secretary of War Edwin M. Stanton. In relating the military history of such special units the study determines what contributions and significance they made to the Union war effort.

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.