Lewis Henry Morgan was an American anthropologist who made significant contributions to the fields of ethnology and anthropology. Various synonyms that can be associated with him are social evolutionist, cultural evolutionist, ethnologist, and historian. Morgan believed in the evolution of human society from primitive to modern times. He argued that human societies go through three main stages of development - savagery, barbarism, and civilization. Morgan's work on kinship and social organization among indigenous nations profoundly influenced the field of anthropology, making him a highly respected figure in the field. He is often referred to as the father of modern American anthropology.