The study draws on longitudinal data covering four years of college among a sample of students from low-income backgrounds, with histories of adverse childhood experiences, who enrolled at more than 150 four-year institutions. Analyses investigate factors that influence the emergence and development of students' sense of campus belonging, with findings highlighting the importance that having a mentor plays in early college levels of sense of belonging, and the positive developmental effects of campus involvement over four years of college. Results indicate that first-generation students enter college disadvantaged in terms of their sense of belonging, which grows more pronounced over four years. Campus involvement appeared to exert a less positive influence in cultivating sense of belonging among first-generation students than among their continuing-generation counterparts. Because of the low-income characteristic of our sample, the disadvantages found among first-generation students may be attributable to the specific qualities that accompany being a first-generation college student, rather than broader notions of family income or social class.