Abstract: Immigrants from Western Europe to the United States are commonly assumed to be racially white. Almost no attention has been paid, however, to recent changes occurring within the composition of the Western European immigrant population: individuals who were born in Western Europe but whose families have origins outside of Western Europe have been migrating to and settling in the US in growing numbers. This study examines the growing diversity of this migratory stream, investigating seven groups of immigrants from Western Europe to the US. I analyze data from the European Social Survey, the US census, the American Community Surveys, the Migrant Integration Policy Index, the UN database, and the World Bank database. First, this study analyzes these origin groups' economic and social characteristics' within Western Europe. I show that while immigrants within Western Europe present an improvement in economic indicators over time and generations, they show no improvement in social indicators. Furthermore, immigrants from less developed regions report on higher rates of being socially excluded, which, in turn, correlate with lower economic achievements. Furthermore, I disentangle the economic `ethnic penalty' of minorities in Western Europe by dividing it into four components: individual characteristics, country characteristics, the social environment in host country, and the policy environment in host country. Then, I analyzed the 'educational penalty' of minority youths in Western Europe and its nature. I show that only intercultural policies help in advancing minorities in Western Europe, due to the poor social acceptance they experience. Given this background on the condition of minorities within Western Europe, I turn to investigate the move that some of them make to the US. I show that immigrants from Western Europe of non-European descents carry a higher `ethnic penalty' when they come to the US, but most of them advance faster economically than the majority of Western Europeans who migrate to the US. I test three plausible explanations for this phenomenon, finding that the level of discrimination experienced by a given ethnic group is the most determinant factor. Minorities who experience a higher discrimination level in Western Europe integrate faster in the US. Social differences between Western Europe and the US, therefore, appear to affect immigrants and their integration patterns. This phenomenon represents a new type of migration: `social migration'. While immigration has been understood overwhelmingly in terms of the two fundamental categories of economic and political (refugee) immigration, the new category of social migration is now emerging between them. I end with examining the far-reaching implications of this new development.