Although research provides ample evidence of teaching methods that facilitate students' learning of specific word meanings, the potential of instruction to impact students' general vocabulary knowledge has remained an unanswered question. This article reports on a three-year formative experiment that developed, implemented, and tested a long-term, multifaceted vocabulary instruction program in a third-grade classroom. Specifically, it presents quantitative findings that demonstrate greatly accelerated growth in general vocabulary, in comparison to the norming sample of a standardized vocabulary test, for three consecutive classes of students and qualitative findings that illuminate the students' participation in the vocabulary instruction and the teacher's expanding vision for and skill in teaching vocabulary. The authors conclude by discussing the significance and the limitations of these findings and highlighting the specific ways that their uniquely successful intervention may inform future research aimed at enhancing elementary students' vocabulary development.