The significant event marking the start of Helen Keller's breakthrough in education was her meeting with her teacher, Anne Sullivan, in 1887. Sullivan employed innovative methods to communicate with Keller, who was both deaf and blind. The famous moment occurred when Sullivan spelled "water" into Keller’s hand, awakening her to the concept of language and leading to a profound understanding of the world around her. This relationship was foundational in Keller’s later achievements and activism.