This study examines textbooks as pedagogical archives in the history of teaching Indonesian in the United States. Employing the History of Language Learning and Teaching (HoLLT) framework, it investigates how pedagogical patterns are transmitted, recontextualised, and maintained over time through two historically linked textbooks by Toenggoel Siagian: Bunga Rampai Bahasa Indonesia (1970) and Satu Bahasa Kita (2021). These textbooks were selected because they were written by the same author across different instructional periods and represent a specific pedagogical lineage connected to the early development of Indonesian instruction in the United States. Employing close reading and comparative historical analysis, the study analyses pedagogical orientation, material organisation, language representation, instructional logic, historical context, and selected textbook excerpts. The findings reveal that despite differences in period, learner level, and instructional purpose, both textbooks preserve a structural pedagogical approach. This continuity functions not as static repetition but as persistence with adaptation, in which structural pedagogy is reconfigured from advanced, reading-based instruction to beginner-oriented communicative practice. The study identifies three dimensions of pedagogical DNA, understood as recurring pedagogical patterns and institutional traces embedded in teaching materials: structural-linguistic DNA, geopolitical DNA, and pedagogical-institutional lineage. These findings indicate that textbooks not only document pedagogical practices but also actively shape, stabilise, and transmit specific forms of pedagogical knowledge. The study contributes to HoLLT by extending the concept of pedagogical DNA beyond teacher practice and by positioning textbooks as dynamic archives for tracing continuity and change within a specific lineage of Indonesian language pedagogy in the United States.
