Since its founding in 1903, the Massachusetts Nurses Association (MNA) has been the most powerful and effective voice on nursing and health care in the Commonwealth. MNA created the Nurse Practice Act, the RN license designation, developed a uniform curriculum for the education of nurses, wrote the first code of ethics for nurses and passed, or helped to pass, nearly every state law governing nursing practice including the law allowing nurses to unionize in Massachusetts. Today, the MNA is the largest union and professional association of registered nurses and health professionals in the state, and the third largest in the nation, representing more than 23,000 members working in 85 health care facilities, including 51 acute care hospitals, as well as a growing number of nurses and health professionals working in schools, visiting nurse associations, public health departments and state agencies.