Illiteracy is a huge problem, socially, economically and educationally. This study of the history and current practices of American public libraries examines their role in supporting the development of human literate abilities and in helping all Americans to be critically literate in order to participate fully and successfully in our society. This exploration begins with the history of libraries in the United States, developments over time and the current practices of public libraries. These practices are explored to see how libraries contribute to the goal of improving adult literacy in America. (Contains 6 endnotes.)