Social workers, educators, psychologists, sociologists, and other social planning professionals have been concerned about the children of immigrants for over a century. In the late 19th and early 20th centuries, social policies and practices toward immigrant families were based on negative assumptions about immigrant culture that characterized immigrants as "peasants" who needed to be "Americanized." This article explores how policies and practices evolved over the first half of the 20th century in response to changing perceptions of immigrant culture and new theories of child development.