He published his "They Came Before Columbus" in 1976, as a Rutgers graduate student. The book deals mostly with his arguments for an African origin of Mesoamerican culture in the Western Hemisphere. Published by Random House rather than an academic press, "They Came Before Columbus" was a best-seller and achieved widespread attention within the African-American community for his claims of prehistoric African contact and diffusion of culture in Central and South America. It was generally "ignored or dismissed" by academic experts at the time and strongly criticised in detail in an academic journal, "Current Anthropology", in 1997.