Findings from the first wave of a longitudinal in-home survey of families who have received Welcome Baby home visiting—a locally designed family strengthening program funded by First 5 LA—indicate that participation in Welcome Baby home visiting is associated with increased likelihood of attempted breastfeeding and exclusive breastfeeding during the first four months postpartum; stronger support networks; higher quality home environments and more frequent engagement in home learning activities; and reduced risk of developmental delay. This work is part of a six year, mixed methods evaluation of Welcome Baby and a broad place-based investment known as Best-Start LA.