The influential educator who founded the first kindergarten in the United States is Elizabeth Peabody. She was instrumental in introducing the concept of kindergarten, which emphasized the importance of early childhood education and play in learning. Peabody opened the first kindergarten in Boston in 1860, inspired by the Froebel method from Germany. Her advocacy for children's education helped shape early childhood programs across the nation. Additionally, Peabody’s efforts contributed to the broader recognition of women’s roles in education and influenced future educational practices focused on developmentally appropriate learning.