Though debates over immigration have waxed and waned in the course of American history, the importance of immigrants to the nation's identity is imparted in civics classes, political discourse, and television and film. We are told that the United States is a "nation of immigrants," built by people who came from many lands to make an even better nation. But this belief was relatively new in the twentieth century, a period that saw the establishment of immigrant quotas that endured until the Immigrant and Nationality Act of 1965. What changed over the course of the century, according to historian Robert L. Fleegler, is the rise of "contributionism," the belief that the newcomers from eastern and southern Europe contributed important cultural and economic benefits to American society.

Early twentieth-century immigrants from southern and eastern Europe often found themselves criticized for language and customs at odds with their new culture, but initially found greater acceptance through an emphasis on their similarities to "native stock" Americans. Drawing on sources as diverse as World War II films, records of Senate subcommittee hearings, and anti-Communist propaganda, Ellis Island Nation describes how contributionism eventually shifted the focus of the immigration debate from assimilation to a Cold War celebration of ethnic diversity and its benefits—helping to ease the passage of 1960s immigration laws that expanded the pool of legal immigrants and setting the stage for the identity politics of the 1970s and 1980s. Ellis Island Nation provides a historical perspective on recent discussions of multiculturalism and the exclusion of groups that have arrived since the liberalization of immigrant laws.