Background: More than a third of American children and adolescents are overweight or obese. Because childhood obesity is a risk factor for various health, mental health, and socioeconomic problems in adulthood, health practitioners, policy makers, and researchers continue to identify growth trajectories and clarify risk factors for unhealthy growth trajectories. The purpose of this dissertation was to identify subcategories of children who follow different body mass index (BMI) trajectories, describe these groups, and explore whether adverse childhood experiences (ACEs) predict group membership. Methods: A sample of children who participated in the Longitudinal Studies on Child Abuse and Neglect (LONGSCAN) study at the Eastern site (Baltimore, MD), and whose demographic and BMI data were collected at age four, were included in the study (n=201). Latent Class Growth Analysis (LCGA) was used to examine longitudinal patterns of BMI growth over a span of 14 years (4 years - 18 years). Data were assessed and the optimal number of classes to describe the growth trajectories was selected. Bivariate and multivariate data analyses were used to describe the children in each group. Multinomial logistic regression was used to examine whether the number of cumulative preschool (age 4) or school-aged ACEs (ages 4 to 14) predicted group membership. Results: Overall, the percentage of overweight/obesity increased with each additional wave. Based on z-BMI score, at age 4, 20.1% were overweight/obese. A marked increase was identified when children were 12 years old (42.0%) and then at 18 years (49.4%). Three BMI growth trajectories were identified: expected growth, emerging overweight, and increasing obesity. Most children followed an expected growth trajectory (73.6%). However, about a fifth followed a trajectory with a steep increase in BMI over time (emerging overweight = 21.9%) and a small percentage of the children exhibited a high initial BMI as well as a high rate of increase (increasing obesity = 4.5%). Ages 8 to 12 and ages 16 to 18 had especially steep slopes when it came to BMI increase in the emerging overweight and increasing obesity trajectories. A higher preschool ACEs score was associated with a low odds ratio of being in the emerging overweight group compared to the expected growth group; school aged ACEs score did not predict membership to a particular class. Female children and those with a higher primary maternal caregiver BMI when the children were 4 years old predicted being in the emerging overweight group compared to the expected growth group. Implications: The time periods that are especially sensitive to steeper weight gain are likely to be the time periods when interventions should be targeted for children in a low income, urban, largely African American community. The current study had results that were divergent from the hypothesis in that children who had higher ACEs at age four were less likely to have an obesity-prone BMI trajectory. Reasons and implications are discussed. The child's gender and the child's maternal caregiver's weight status should provide some guidance in intervention and treatment decisions.