In the USA, authority over teacher education and certification rests with the individual states rather than the federal government. Nonetheless, US mathematics teacher-education programs bear a strong resemblance in their fundamental structure to one another and to the earliest such programs established in the 1890s. This paper examines an influential early program developed by David Eugene Smith, a pioneer in mathematics education. Smith's program required preparation in mathematics, specialized training in mathematics pedagogy, exposure to social science perspectives and supervised practice teaching. Three characteristics distinguished Smith's program: the importance of a historical perspective, the dynamic aspect of the teacher's role, and the need for an international viewpoint. Smith sought to extend the domain of teacher education into school classrooms through his innovative handbooks for teachers. An examination of Smith's 1904 arithmetic series and the accompanying handbook reveals how he incorporated the continued education of teachers into school textbooks.