Diversity is a common feature of Western societies, especially in urban areas, and particularly because as immigration continues to transform nations, integration grows as an area of practice and research. Conventional “assimilation” perspectives, which center on a linear path that immigrants travel to become part of the host society, have been challenged by scholarship that finds immigration to be a dynamic and synergistic process. “Immigrant integration” is not a static or narrowly defined term but rather an inclusive description of the dynamic three-way process of change for the migrant, the sending country, and the receiving community. The increase of immigrants, especially beyond the traditional gateway cities, and responses to newcomers have led to the development of new social constructs, contesting older ones, to capture the complex patterns of inclusion and exclusion of distinct immigrant ethnic groups residing in varied settings across the United States. “Integration” as a term is suggestive not of all becoming part of a single culture but rather a process of affirming cultures that combine within the diverse and enriched nation that results. Oscar Handlin wrote in The Uprooted (1951:3) that “Once I thought to write a history of the immigrants in America. Then I discovered that the immigrants were American history.” No single academic disciplinary lens provides a complete grasp of immigration, and it is the confluence of disparate theories and methods that sharpens knowledge and insights about the “who, what, and why” of the immigration process and its consequences. The stresses on contemporary society created by significant demographic changes have led to a quest for a more nuanced understanding about the patterns of settlement, the cultural reactions stimulated by these population shifts, and the impact immigration has on education, health, the marketplace, and the democratic institutions of the state. Selected works in this article express the vast array of issues and approaches to understanding the dynamic processes impacting the more than forty-four million residents of America who are foreign born. In recognition of social work as a primary career serving newcomers, this article displays the breath of the theory, methods, issues, implications, and culturally sensitive interventions related to migration. Social workers, educators, and religious leaders are first responders, and presenting these professionals with evidence-based analysis equips both providers and policymakers with the knowledge to facilitate the full social, civic, and economic integration of foreign-born residents. A few comparative works that both acknowledge the unique history of the United States and the global nature of migration are included. There is a complementary body of work in immigration law outside this article, and there are an increasing number of law schools partnering with social work schools to integrate practice. The subject of the “second generation” has not been included, although they warrant a distinct entry. Current political debates and continuing issues of oppression and prejudice also merit an article in themselves. No list can do justice to the wealth of scholarship available, nor even the various experts and emerging scholars, but this effort is offered to ground pursuits in the breadth of approaches and subjects relevant to the field.