The growth of our knowledge of diseases of the kidney has been the work of brilliant individuals of talent and passion, who have become some of the most respected and best remembered figures in nephrology. Unfortunately, we often forget that in many cases there were others, no less brilliant, whose vision and passion to study diseases of the kidney was no less intense but whose contributions have been forgotten. Francis Delafield (1841-1915) is one of those important but overlooked figures. An 1863 graduate of the College of Physicians and Surgeons, he continued his studies in London and Berlin, and upon his return to New York became a pioneer in histopathology in general and that of kidney disease in particular. He provided detailed and accurate microscopic descriptions of kidney pathology, made a concerted effort to correlate clinical signs and symptoms with kidney lesions and provided a nosological classification of the acute and chronic forms of what was then known merely as Bright's disease. During his life, he was recognized as the American authority on diseases of the kidney and the City of New York acknowledged his contributions by naming a hospital after him.