This dissertation is a comparative study of the politicization process among French migrants who settled in two major Atlantic port-cities, New York and New Orleans, during the first half of the 19th century.In an Atlantic perspective, the politicization process is analyzed as the development of national consciousness, which is visible in the relationship between migrants and their home country – from the First to the Second Napoleonic Empire – and their place of settlement, in the context of the Early republic, the Jacksonian and the Antebellum eras. Atlantic circulations influenced the rise of sociability structures among Frenchmen in these cities, such as masonic lodges. Migrants also experienced multiple forms of participation to major local, national or international events on both sides of the Atlantic, sometimes in a conflicting way.Three periods thus emerge. First, the mixing and gathering of French migrants in both cities were related to the Atlantic revolutions and their 19th-century political impact. Secondly, the expansion of political parties and practices, under the July Monarchy and Jacksonian democracy, led to the reinforcement of national consciousness, without excluding multiple affiliations. Finally, the Atlantic dimension of the 1848 revolutions generated new political tensions. Mass migrations and working-class movements shaped emerging conflicts in the industrial era. In that same period, momentous American issues provoked diverging evolutions between New York and New Orleans. French migrants in both cities were divided on the North-South debate on slavery, as their national and political allegiances were questioned by the Civil War.
