This was the first time that the Olympics were organised at this altitude: 2240 meters above sea-level. The thin air led to some exibitional achievements like the 8.90m long jump by Bob Beamon (USA) and the olympic and world record 4x400m relay men that lasted for 22 years. There was the black power incident in the 200m victory ceremony. The Americans Tommie Smith (1st) and John Carlos (3rd) raised black-gloved fists during the playing of the American anthem. They were both send home by the IOC. Compared with the Nazi-games in 1936 they did not do anything weird, some sources said. Clearly athletes that were used to thin air had a comparative advantage, such as Kenyans and Ethiopians, but in general it was a fait competition. South Africa was banned for ever from the Olympics due to a threatening boycott of 40 countries, mainly African, as long as apartheid lasted. The Soviet Union invaded Czechoslovakia in august 1968 to suppress the Czech political "springtime": however no boycotts were imposed or proposed. Student riots at the University of Mexico City were beaten down at the cost of dozens killed and many students injured. Last but not least in the US athletes were summoned to protest against the bad treatment of black people in the US in general. Smith and Carlos did as we know now.