Across America, an ongoing crisis of reading underachievement exists for many African American students; reading skill proficiency is not being achieved at levels on par with their grade-level peers. The problem addressed in this study was African American students who have not met the minimum passing score on state tests are placed in reading intervention courses that have not been documented as effective pathways to achieving grade-level proficiency on subsequent iterations of the state assessments. The purpose of this quantitative causal-comparative study was to measure the effectiveness of high school reading intervention courses to ameliorate the English I and English II state standardized assessment scores of African American retesters. Threat rigidity effects theory provided the framework for this study. Archival data that consisted of the raw scores of 1,816 African American high school English I and English II retesters from the 2018-2019 school year were used to gauge the effectiveness of reading intervention courses. Utilizing an independent samples Mann-Whitney U nonparametric test, the mean scores of students enrolled in reading intervention courses were compared to those not enrolled. Data analysis revealed no statistically significant difference in means for the English I or II retesters; therefore, the courses were not effective. Implications included factors such as entry and exit criteria and motivation, which can influence or obstruct student success. School leaders need to collaboratively examine and develop stable criteria for student placement and proficiency. Future researchers should explore the effect that students' social emotional experiences and student literacy identity has upon their success with reading intervention courses. Reading intervention courses must be effective and applicable because for African American students, the stakes are high. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]