This second edition updates material in the first edition for another decade to 1990 and responds to criticisms of findings in the first edition. This book investigates teaching practices before, during, and after 20th-century reform efforts aimed at changing what teachers routinely do. Patterns of stability and change over a 100-year period are developed from evidence from a wide variety of sources, including classroom photographs, textbooks and tests used, student recollections, teacher reports of how they taught, and classroom observations by parents and administrators. Descriptions of teacher-centered and student-centered instructional practices, as well as possible hybrid approaches, provide a tool to help map the intricate complexity of classroom practices. Part I covering 1890-1940 consists of five chapters that describe teaching at the turn of the century, including progressive reforms of that era; provide case studies of classroom practices in New York City (New York), Denver (Colorado), and Washington, D.C. during the 1920s and 1930s; and survey teaching practices nationally during those 2 decades, particularly in rural schools. Part II summarizes case studies of informal and open education in Washington, D.C., New York City (New York), and North Dakota during 1965-75, and provides local (Arlington, Virginia) and national snapshots of classroom practices during 1975-90. Part III examines six possible explanations for continuity or change in teaching during this century and discusses implications for policymakers, practitioners, and researchers. The possible explanations are: (1) cultural beliefs about the nature of knowledge, teaching, and learning; (2) organization and practices of schooling related to socialization and sorting of students; (3) flawed implementation of instructional reforms; (4) effects of organizational structures; (5) culture of teaching, which leans toward stability; and (6) effects of teachers' knowledge and beliefs. This book contains over 400 references, photographs, and an index. (SV)