This case study evaluated the significance of implementing an enrichment mathematics course during the summer to rising African American ninth graders entitled, "Geometry Honors Preview." In the past, 60 to 70 percent of African American students in this school district had withdrawn from Geometry Honors by the second academic quarter. This study seeks to understand the impact of pre-teaching core geometry concepts essential to success in Geometry Honors prior to the students' enrollment into the Geometry Honors course. This mixed methods case study involved the researcher as a participant observer. Qualitative data in the form of questionnaires administered to teacher assistants, students, and their parents comprised a significant part of the data collection. Additional qualitative data collection included field notes, teacher's comments from report cards, and informal interviews of the instructor of the Geometry Honors Preview course. Quantitative data gathered from the four quarterly report cards completed the data collection process. The study concluded that all of the students who enrolled in the Geometry Honors Preview course successfully completed Geometry Honors during the school year. Students felt more confident about enrolling into Geometry Honors after taking the preview course. Finally, African American students who enrolled in the Geometry Honors Preview course outperformed a group of African American students who enrolled into Geometry Honors, but did not attend the summer course. Using current research into the topic of closing the achievement gap, the study suggested that these findings would help improve the practice of teachers and implement policy that will provide all students with an equal opportunity to learn in an environment of high-stakes testing. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]