During the years 1840-1930, the population of the United States grew more than at any other period in its history, largely because of the influx of immigrants from Europe. The newcomers, because of their background and their numbers, were considered a challenge to American national identity, and the movement to make the immigrants into Americans matured in direct response to their arrival. Consensus over what ‘American’ values were, proved elusive, though this did not diminish the zeal with which a large number of institutions, people, and communities became engaged in the massive attempt to teach ‘Americanism’ and ‘American citizenship’ to immigrants and to convert as many into ‘real’ Americans as possible. The movement for Americanisation which began as the articulation of a general mistrust of the newcomers’ ability to assimilate culturally and politically, became a highly organised attempt to educate, indoctrinate and convert immigrants to American modes of political behaviour, workplace docility and social conformity by the time the First World War reached its apex. But the official Americanisation movement disintegrated quickly after the war as Federal funding ended in 1919. Very little is known on the continuing Americanisation movement or its afterlife in the 1920s and 1930s. The following essay will show how Americanisation lived on in the two decades after First World War, within communities of immigrants largely outside the influence of Federal programs. During this period the structure and meaning of Americanisation for immigrants changed in important ways from something ordered by the government to a process immigrants, shaped for themselves. In many ways my essay will build on an emerging new historiography which has focused on the creation and re-shaping of Americanisation by those who were traditionally thought of as mere objects of the crusade: working-class immigrants. ‘Americanisation from below’ as my colleague James Barrett has called it, took less institutional forms. Instead, it was rooted in social and community life. Seen this way, Americanisation was a localised, evolutionary process, difficult to fix in terms of chronology or milestones. Acquiring political and legal citizenship through naturalisation, for example, was just one of the many ways that immigrants choose to respond to the call for Americanisation. Learning the language, associating with other Americans and adopting other parts of what were considered American value systems were equally important.