The document summarizes the historical evolution of social work in the United States from the colonial period to the present. It outlines the major periods and developments, including early charity organizations in the 17th century, the growth of children's aid societies and organizations preventing cruelty to children during the industrial revolution, the establishment of scientific charity organizations and training schools for social workers in the late 19th century, and the increased professionalization of social work as a discipline along with the creation of federal relief programs during the Great Depression in the 20th century.