This dissertation explores the impact of the classroom environment on undergraduate engineering students by integrating three manuscripts using the process-person-context-time (PPCT) model within Bioecological Systems Theory. Each manuscript focused on students' sense of belonging, motivation, and academic confidence. The study confirms prior research suggesting a link between students' perceptions of the environment and their sense of belonging, motivation, and academic confidence. The findings highlight the complex nature of student and classroom environment relationships throughout their college experience. Moreover, the results are demonstrated across different engineering majors. Chapters two and three utilize secondary data analysis to examine student perceptions of the classroom environment in a specific engineering major. Those results underscored the importance of students' perceptions, which significantly predict students' sense of belonging, motivation, and academic confidence. A key finding suggested sense of belonging as a mediator for juniors and seniors. This emphasized the need to foster a positive classroom environment throughout students' academic journey. Results from chapter three revealed non-linear trends in students' perceptions, indicating fluctuations within the classroom environment over time. Chapter four collected from sophomores, juniors, and seniors across five engineering majors. That explored the relationships between classroom environment perceptions, sense of belonging, motivation, and academic confidence, while also considering negative daily life experiences, such as racial and nonracial microaggressions. Results indicated direct and indirect effects of negative daily life experiences on students' sense of belonging, motivation, academic confidence, and their perceptions of the classroom environment. Moreover, the results supported prior research concerning the existence of a unifying engineering identity regardless of major. Overall, this dissertation highlights the significance of understanding the complex interactions between students and their classroom environments in engineering education. It emphasized the need to create more inclusive and supportive classroom environments that have the ability to enhance students' sense of belonging and motivation. These findings have implications for engineering educators seeking to foster positive learning experiences for all students, regardless of their background or major. [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.]