Nebraska Man was a fossil discovery that was regarded by several leading experts as important in understanding evolutionary history. The only evidence for this anthropod was a single tooth (which turned out to be a pigs' tooth). The discovery and controversy surrounding the Nebraska Man (Hesperopithecus haroldcookii hominoidea) fossil find and its importance in history are reviewed. Its supporters' writings reveal the critical role that preconceptions played in interpreting the limited evidence. Nebraska Man provides a valuable lesson on the importance of presumptions in interpreting evidence in the field of human origins. It also stresses the need for careful evaluation of the empirical evidence for new ideas, and the danger of going beyond what the facts warrant.