In 1900, 11 years after the founding of the Brazilian Republic, the Kayapo population was about 4,000. As miners, loggers, rubber tappers, and ranchers poured into the Brazilian frontier, missionary organizations and government agencies launched efforts to “pacify” aboriginal tribes, wooing them with trade goods such as cloth, metal pots, machetes, and axes. Contact often had the unintended effect of introducing measles and other diseases to people who had no natural immunity. By the late 1970s, following the construction of the Trans-Amazon Highway, the population had dwindled to about 1,300.