Mary Mitchell Slessor (1848 – 1915). Scottish Presbyterian missionary to Nigeria. Once in Nigeria, Slessor learned Efik, one of the numerous local languages, then began teaching. Because of her understanding of the native language and her bold personality Slessor gained the trust and acceptance of the locals and was able to spread Christianity while promoting women's rights and protecting native children. She is most famous for having stopped the common practice of infanticide of twins in Okoyong, an area of Cross River State, Nigeria.