We evaluated a curriculum that focused on bolstering grit and locus of control in seventh grade students at a school in upstate New York. The intervention included lessons aimed at building a growth mindset and determination, along with writing projects and collaborative work. A pre-post design was utilized such that surveys measuring grit and locus of control were administered at the beginning of the school year and at the end of the school year for 215 students. Participants also completed standardized tests in reading and math. Students' scores on locus of control showed a significant change toward higher perceived control. The lowest scoring students on grit also showed a significant increase over the same time period. No changes were observed at a comparison school that did not receive the intervention. Both grit and locus of control significantly predicted academic achievement on standardized tests for reading and math. The findings support the intervention and the importance of grit and locus of control in academic achievement.