Background: Breastfeeding initiation and duration is associated with better immunologic status and neurodevelopment for the breastfed infant in both the short- and long-term. Literature consistently illustrates lower rates of breastfeeding in low-income populations, including those participating in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC). Socioeconomic determinants of breastfeeding initiation and continuation within a cohort at-risk for low breastfeeding rates remain unknown. Objective: To characterize socioeconomic determinants of breastfeeding initiation and continuation to 3 months postpartum in a Midwestern cohort of families living in poverty. Method: The Kids in Columbus Study (KICS) measures access and use of community resources during the first five years of life. KICS participants (n=322) were recruited from WIC locations during pregnancy through 3 months postpartum. Data analyzed here were collected at enrollment and approximately 6 months later when the infant was between 4 and 7 months of age. Caregivers (98.6% mothers) reported infant feeding practices (i.e., breastfeeding, formula feeding, solid foods introduction) and completed a socioeconomic profile. Breastfeeding initiation and continuation to 3 months postpartum was examined in relation to sociodemographic variables, institutional resources (e.g., checking account, savings account), economic hardship (e.g., difficulty paying bills), and food insecurity using log-binomial regression to estimate relative risk (RR). Results: The average age of the 212 (56%) caregivers who participated in both data collection timepoints was 26.6 (SD=5.1) years, 49% reported a high school or lower level of education, 58% were unemployed, 59% were single, and 66% reported an annual household income below $20,000. Children were 57% female, 41% black, and 7% Hispanic. Approximately 75% of mothers initiated breastfeeding, 42% of the cohort breastfed (BF) and 12% exclusively breastfed (EBF) to 3 months postpartum. Lower likelihood of breastfeeding initiation and continuation was associated with lower educational attainment (RRInitiation=0.76, 95% CI: 0.64,0.89; RRBF=0.68, 95% CI: 0.48,0.96) and being single (RRBF=0.55, 95% CI: 0.40,0.77; RREBF=0.43, 95% CI: 0.21,0.90). Caregivers who reported losing utility service in the past year (RR=1.20, 95% CI: 1.03,1.34) and difficulty affording balanced meals (RR=1.17, 95% CI: 1.01,1.36) were more likely to initiate breastfeeding. Caregivers who reported food not lasting (RRBF=1.65, 95% CI: 1.19,2.29), difficulty affording balanced meals (RRBF=1.41, 95% CI: 1.02,1.94), and adults skipping meals due to financial reasons (RRBF=1.47, 95% CI: 1.07,2.02) were more likely to continue breastfeeding to 3 months postpartum. Conclusions: Although the majority of mothers in this low-income sample initiated breastfeeding, less than half continued breastfeeding to 3 months postpartum, with a very small percentage exclusively breastfeeding as recommended by the American Academy of Pediatrics. Targeted support for single mothers and mothers with lower levels of education may lead to higher rates of breastfeeding initiation and continuation, especially for families living in poverty.