To commemorate the 50th anniversary of the Emergency Nurses Association, this article describes the 3 most enduring and impactful policy initiatives in the organization's history. These initiatives were identified through a comprehensive review of the articles published in the Journal of Emergency Nursing as well as in other publications of the Emergency Nurses Association, including position statements and press releases. The top 3 policy issues throughout the Emergency Nurses Association's history were identified as provision of care for vulnerable populations, trauma and injury prevention, and patient quality and safety. The Emergency Nurses Association also worked hard to professionalize emergency nursing within the realms of nursing and emergency services during the first half of its history, and since then the Emergency Nurses Association has promoted issues related to the emergency nursing workforce and to ensuring a safe and sustainable environment in which nurses practice. This article includes critical constructs such as the professionalization of emergency nursing; advocating for vulnerable populations such as children, older adults, and people experiencing sexual violence or human trafficking; improvements in trauma care and injury prevention; promoting quality and safety through nursing certifications, efficient and accurate nurse triage, and disseminating best practices in evidence-based care; and supporting the nursing workforce by championing issues such as workplace violence, ED crowding, and healthy work environments.