Public health nursing is the oldest branch of nursing in the world. The word nursing itself is derived from the Latin “nutrio,” meaning to nourish. Since the infant, child, young adolescent must have a nourishing diet, adequate care and supervision to reach strong, healthy, happy adulthood, we find that mothers were the first public health nurses. From this we might expect to find maternity or child welfare as the basis of preventative nursing. Instead, we find the old law of mutual aid asserting, and the foundation is laid on the visiting of the poor and sick poor. We are able now to trace the slow progress of public health nursing through the years, oftentimes almost completely submerged by ignorance and superstition up to the present-day programs.