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 study analyzes the procedures and operations of the Quartermaster, Ordnance, Commissary, and Medical Departments during Scott's campaign to determine the efficiency of the prevailing logistical system. Unpublished and published government documents, official records, manuscript collections, memoirs, diaries, and newspapers provide the data. The first chapter describes the logistical departments interworkings; the remaining chapters detail the operations of the bureaus during the expedition's assembly and campaign against Mexico City. The evidence revealed organizational deficiencies which caused severe shortages, particularly in transportation, for Scott's army. The shortages severely hampered the expedition. Because of .the numerous victories over 'Mexican forces, however,. American leaders ignored the organizational deficiencies, These shortcomings reappeared to .impede operations during the Civil War.