Breastfeeding is the optimal source of nutrition for most infants (1). Although breastfeeding rates in the United States have increased during the past decade, racial/ethnic disparities persist (2). Breastfeeding surveillance typically focuses on disparities at the national level, because small sample sizes limit examination of disparities at the state or territorial level. However, birth certificate data allow for assessment of breastfeeding initiation among nearly all newborn infants in the United States both nationally and at the state and territorial levels. To describe breastfeeding initiation by maternal race/ethnicity,* CDC analyzed 2019 National Vital Statistics System (NVSS) birth certificate data for 3,129,646 births from 48 of the 50 states (all except California and Michigan^†), the District of Columbia (DC), and three U.S. territories (Guam, Northern Mariana Islands, and Puerto Rico). The prevalence of breastfeeding initiation was 84.1% overall and varied by maternal race/ethnicity, ranging from 90.3% among infants of Asian mothers to 73.6% among infants of Black mothers, a difference of 16.7 percentage points. Across states, the magnitude of disparity between the highest and lowest breastfeeding rates by racial/ethnic groups varied, ranging from 6.6 percentage points in Vermont to 37.6 percentage points in North Dakota, as did the specific racial/ethnic groups with the highest and lowest rates. These state/territory-specific data highlight the variation that exists in breastfeeding disparities across the United States and can help public health practitioners and health departments identify groups on which to focus efforts. Targeting breastfeeding promotion programs on populations with lower breastfeeding rates might help reduce racial/ethnic disparities in breastfeeding initiation and improve infant nutrition and health.