This pilot study aimed at developing and validating an evaluation model to assess the impact of participation in the National History Day in Ohio program (NHD-OH) on students academic achievement and intellectual growth by using as key indicators: a) High-stakes tests, i.e., Ohio Graduation Tests (OGT) in Social Studies, Reading and Writing; b) Appreciation of history, and c) Development of critical thinking. Using a quasi-experimental study design, twenty-four tenth-graders participating in NHD-OH and twenty-four matched controls were used in the analysis to reduce the impact of selection bias. As a result of this study it was found that students participating in NHD-OH received statistically significant higher scores on the Social Studies OGT, reading and Writing; and furthermore, demonstrated a deeper appreciation of history and a better ability to explore and integrate new perspectives. (Contains 11 tables, 1 figure, and 16 notes.)