Lesson One discusses the evolution of evidence-based practice in nursing from Florence Nightingale to the 21st century. Key developments include Nightingale utilizing statistics to support patient care improvements during the Crimean War in the early 1900s. During the 1950s-1960s, emphasis was placed on defining the nursing role and specialty areas through research. The 1970s saw a focus on evaluating nursing education methods and practice levels. In the 1980s-1990s, clinical journals emerged and research-based interventions were developed. Today, nursing focuses on quality studies, evidence-based practice, and health promotion.