Walter Dandy was an influential American neurosurgeon born on April 7, 1886. He is best known for his pioneering work in the field of neurosurgery, particularly in the development of techniques for brain surgery. Dandy contributed significantly to the understanding of brain tumors and hydrocephalus, and he was one of the first to use the ventriculostomy procedure. Throughout his career, Dandy published numerous scientific papers and trained many future neurosurgeons. He served as the chief of neurosurgery at Johns Hopkins Hospital and was a founding member of the American Association of Neurological Surgeons. His innovations and teachings have had a lasting impact on modern neurosurgery.