An examination of historical developments in western Africa during six climate periods extending over two millennia, this study demonstrates that numerous historical developments correlate with climate periods and/or were influenced by changes in rainfall patterns and ecological conditions. These include such diverse topics as the diffusion of cultigens and domestic animals; movements of language groups; the development of trade routes and the exploitation of mineral, agricultural, and sylvan resources; techniques of warfare and state-building; and numerous other economic, social, and cultural patterns associated with the peoples of western Africa. Data and analyses presented in this study derive from scholarship in many disciplines, including anthropology, art history, folklore, geography, history, and linguistics. Collections of oral traditions and scholarship are also included. Part 1 covers western Africa from c300 B.C.-c300 A.D. in "The Era of Smiths and Riverine Traders," and from c300 A.D.-700 A.D. describing a period of expanding commercial networks. Part 2, "The Era of Savanna Zone," discusses western Africa from c700-1100 A.D. Part 3, "The Era of Power Associations and Mandekalu Horse Warriors," examines western Africa from c1100-1500 A.D. Part 4, "A Brief, But Eventful Wet Period," covers western Africa from c1500-1630 and Part 5, "An Era of Droughts, Famines, Warfare, and Slaving," discusses western Africa from c1630-1860. The document also includes 4 figures and 15 maps. (RSI)