This thesis compares German and Irish immigration to the American Midwest by examining migrant settlement in two of its cities during the period from 1850 to 1900. Concentrating on ethnically German and Irish communities in Fort Wayne, Indiana and St Louis, Missouri, this thesis examines these immigrant communities from a state of transition to settlement and ultimately assimilation through economic, social, cultural, political and religious lenses. By exploring the German and Irish migrant groups in this manner, the diversity of the immigrant experience becomes apparent. Simultaneously, the varying spatial constraints of a smaller city such as Fort Wayne as well as the challenges which faced immigrant communities in larger, significantly more developed urban centres like St Louis is also examined. Five available decennial US Federal Census schedules from 1850 to 1900 provide the framework for this study. Through the analysis and interpretation of the information contained therein, an immigrant profile establishing demographic, residential and economic trends specific to each community is constructed. Specific case studies utilised throughout this study chart the progression and in some instances domination of one immigrant community over the other in their host cities. This dual combination of quantitative and qualitative analysis personifies the immigrant experience German and Irish communities in the America Midwest during the second half of the nineteenth century.