First and second grade public school teachers were trained through interactive video-conferencing to implement "Language Enrichment," an Orton-Gillingham-based literacy instruction. The effectiveness of the linguistically informed training was demonstrated by documenting the longitudinal third grade reading comprehension achievement of their students. Student achievement was measured on the state-mandated achievement test, Texas Assessment of Academic Skills (TAAS). Hierarchical linear modeling (HLM) showed that students whose teachers were trained in Language Enrichment instruction had higher third grade reading comprehension achievement than students whose teachers were not trained. Additionally, a significant effect of the length of "Language Enrichment" teaching experience of the second grade teacher on third grade reading comprehension was found. Earlier occurring second grade teacher training was associated with higher reading scores than later training. Based on these findings it is suggested that teachers who have content-rich knowledge known to support literacy acquisition can provide reading instruction that results in a level of reading comprehension that is significantly higher than that resulting from teachers who do not have a well-developed domain of knowledge concerning the reading process. This study also indicates that teacher competence was enhanced through practice because student reading achievement of the more-experienced "Language Enrichment" teachers was higher than that of the less-experienced "Language Enrichment" teachers.