Every student comes into each classroom with a unique mathematical identity. Mathematical identity consists of the stories about a person's confidence, beliefs, and persistence with mathematics as told by her/himself or by others (Gweshe & Brodie, 2019). Identity is not fixed (Dweck & Yeager, 2019; Wenger, 1998) and is dynamic within a social environment (Langer-Osuna, 2018). The purpose of this study is to investigate mathematical identity, mindset, and social positioning and the mathematical academic achievement of seventh grade students within a rural context. This study uses SEM to investigate the relationships between affect, mindset, positioning and mathematical academic achievement. The factors were founded in the literature and confirmed by exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). A nine-factor model (attitude, value, interest, self-concept, aspiration, anxiety, mindset, adult positioning, peer positioning) was created with acceptable fit (RMSEA = 0.057, CFI = 0.920, TLI = 0.905). SEM results indicate a significant negative relationship between anxiety and aspiration, as well as positive relationships between positioning adult to attitude, positioning peer to attitude, mindset to adult positioning and attitude, aspiration to anxiety and mindset, aspiration to adult positioning and attitude, self-concept to mindset, adult positioning, and attitude, as well as value to aspiration. One-way analysis of variance tests were conducted on these factors by school, teacher, gender, and ethnicity to establish known groups validity. This research adds to the body of work by developing and testing an instrument to investigate students' mathematical identity, mindset, social positioning, and mathematical achievement through SEM. [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.]