The purpose of this study was to examine the effect of the COVID-19 pandemic on ninth-grade students' mathematics achievement in a rural school district located in South Carolina. Students enrolled in ninth grade prior to the COVID-19 pandemic (2018- 2019 school year) Algebra I EOC scores were compared to the students enrolled in ninth grade for the 2021-2022 (post-COVID-19 pandemic) school year. The school district contained eight high schools. The researcher looked at the overall population of the study to determine if there was a difference between mathematics growth pre- and post- pandemic on Algebra I EOC scores. Following that, the researcher examined the mathematics achievement of students based on their gender, race, and socioeconomic status. Findings from this research study revealed that there were significant differences in the mathematics achievement of 9th grade students on the Algebra I EOC assessments between the 2018-2019 (pre-pandemic) and the 2021-2022 (post-pandemic) school years. The post-pandemic Algebra EOC scores were significantly lower than pre-pandemic 9th grade students' Algebra I EOC scores. The data also revealed that there was a significant difference in the mathematics achievement of 9th grade students on the 9th grade Algebra I EOC assessments between the 2018-2019 (pre-pandemic) and the 2021-2022 (post- pandemic) school year as related to gender. However, as related to race and socioeconomic status, the data revealed that there were no significant differences on the mathematics achievement of 9th grade students on the 9th grade Algebra I EOC assessments between the 2018-2019 (pre-pandemic) and the 2021-2022 (post- pandemic) school years. The findings of this research study can aid state, district administrators, and teachers with developing a recovery plan for students. In the future, leaders in the educational system could use the results of this study to develop a more proactive approach if they are forced to socially distance or use distance learning for a long period of time. [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.]