This article analyzes the components of Florence Nightingale's visionary leadership for global health and nursing within the historical context of Great Britain's colonization of India. The descriptive study used the qualitative approach of narrative analysis to analyze selected letters in the Nightingale Letter Collection at the University of Alabama at Birmingham that Nightingale wrote to or about Dr. Thomas Gillham Hewlett, a physician and health officer in Bombay, India. The authors sought to increase understanding of Nightingale's visionary leadership for global nursing and health through a study of the form and content of the letters analyzed as temporally contextualized data, focusing on how the narratives are composed and what is conveyed. Several recurring themes central to Nightingale's leadership on global nursing and health emerge throughout these letters, including health and sanitation reform, collaborative partnerships, data-driven policy development, and advocacy for public health. These themes are illustrated through her letters to and testimony about Dr. Thomas Gillham Hewlett in her vivid descriptions of health education and promotion, data-driven policy documents, public health and sanitation advice, and collaboration with citizens, medicine, policy makers, and governments to improve the health and welfare of the people of India. The focus on leadership in nursing as a global construct highlights the lessons learned from University of Alabama at Birmingham's Nightingale Letter Collection that has relevance for the future of nursing and health care, particularly Nightingale's collaboration with policy leaders, her analysis of data to set policy agendas, and public health reform centered on improving the health and well-being of underserved populations. © The Author(s) 2013.