While famous as a nurse, Florence Nightingale's true genius was in data visualization and medical statistics. During the Crimean War, she realized that more soldiers were dying from poor sanitation and disease than from battle wounds. To prove this to the British government, she invented the 'Coxcomb' or polar area diagram. This visual representation clearly showed that infectious diseases were the leading cause of death, forcing the government to implement massive sanitation reforms. Nightingale was the first female member of the Royal Statistical Society. Her use of data to drive social change saved more lives than her direct nursing ever could, establishing the foundation for modern public health and evidenced-based medicine.