Discussion of the authenticity of materials contained in English-as-a-Second-Language (ESL) textbooks for elementary/secondary school use focuses on content designed to accelerate academic language development and highlights the experiences of one teacher with one textbook. The approach taken is that integrating language and content, while taking into account learners' prior experiences, can create a context for academic language learning in ways that engage learners authentically with meaningful input and the language for making connections with learner realities in both school and community. Definition of authenticity is examined from several perspectives. The textbook discussed is from the "Scott Foresman ESL: Accelerating English Language Learning" series; the chapter highlighted is from a grade 6 unit on dinosaurs that is designed to integrate science and mathematics content, social studies, language arts, and authentic literature. The context in which the materials were used is a middle school ESL class with students of varied linguistic backgrounds. Classroom techniques used to exploit text content (activating and building on prior knowledge, providing cognitively engaging input with appropriate contextual supports, using language actively to connect prior knowledge and thematic content) are described. Standards for assessing the authenticity of textbook content are outlined. Contains 11 references. (MSE)