In the previous chapter I examined the governance of religion within United States public schools from a legal perspective, and religion and school law and policy as practiced by democratic states in international contexts. I also examined and compared across different country contexts key school policies and practices that relate significantly to the religious migrant student. I concluded the chapter with an analysis of legal and policy environments in both the U.S. and international contexts, with attention drawn to the essential themes addressed in Chapter One. I now turn my attention to the multiple roles religion plays in the migration process, in an effort to construct a knowledge base for creating school policies reflecting informed recognition and accommodation. Here I direct attention to specific migrant populations and their religious affiliations from both historical and contemporary perspectives, beginning with an examination of various migrant groups in the United States. I then situate the U.S. within a broader international context. With respect to both the U.S. and countries outside the U.S. I primarily examine religion and integration through the lens of segmented assimilation theory, following the work of Alejandro Portes and Rubén Rumbaut, and of Stephen Warner. However, I also devote some time to examining areas not adequately captured by or involved in the theory. Most notably these involve the place of religious conversion amongst both voluntary and forced migrants, and the important role of transnationalism amongst many immigrant and refugee religious communities. Regarding refugees, I carve out space in this chapter to direct attention to the phenomenon of forced migration as it relates to religion. While much of the existing literature concerning migration and religion does not make careful delineations between immigrants and refugees, I believe refugees constitute a unique population and present unique circumstances and conditions when it comes to religion.