African American youths are overrepresented in the American juvenile justice system relative to Caucasians. Yet, research on antisocial behaviors (ASB) has focused on predominantly Caucasian populations. Furthermore, relatively little is known about how environmental factors, such as supportive parenting (e.g., how close adolescents feel to their parent) and school connectedness (e.g., how supported adolescents feel at school), affect trajectories of ASB in Caucasians versus African Americans. This study mapped developmental trajectories of ASB in Caucasians (n = 10,764) and African Americans (n = 4,091) separately, using four waves of data from the National Longitudinal Study of Adolescent to Adult Health. We then examined supportive parenting and school connectedness on the trajectories of ASB. Four trajectories of ASB were identified for both Caucasians and African Americans: negligible, adolescence-peaked, low-persistence, and high-persistence ASB, although prevalence rates differed by racial-ethnic status. Supportive parenting reduced the risk of membership into the adolescence-peaked trajectory for both Caucasians and African Americans. However, school connectedness was less protective for African Americans than for Caucasians because it only predicted a lower risk of adolescence-peaked membership for African Americans. Findings may reflect the complex social dynamics between race and schools in the development of ASB.