From the 1890s to the 1920s American mathematical research grew substantially in quantity and quality. However, few mathematicians were able to pursue research exclusively; most mathematicians, whether active researchers or not, were employed as teachers by colleges and universities. Their degree of interest in the teaching role varied greatly: while some shunned instructional issues, a few mathematicians became deeply involved not only in teaching undergraduates but in attempting to influence mathematics education in the secondary and even the elementary schools. This book seeks to understand these divisions among the mathematicians regarding pedagogy, to explore alliances and conflicts between mathematicians and other educators, and to explain the resulting effects on educational institutions and on the mathematicians themselves.