Swimming at the 1968 Ciudad de México Summer Games:

Since the 1964 Olympics the world record has been improved 10 times by seven different swimmers, with the most recent mark being 4:06.5, set by Canada’s Ralph Hutton at Lincoln, Nebraska in August 1968. He was considered co-favorite with America’s Mike Burton, a long-distance specialist who was even better at 800 and 1,500 metres. Burton had been sick in Mexico City and almost withdrew, and then started the 400 final by false starting. But when the race started for real he quickly moved to the lead. He and Hutton then exchanged the lead over the next few laps until Burton moved ahead at 300 metres. At that point Burton’s strength proved crucial and he pulled further away on the final two laps to win over Hutton by 2.7 seconds. Alain Mosconi (FRA), twice a world record holder in the event, swam a tactical race for the bronze medal. A few days later, Burton would come back and win the 1,500 metres, a gold medal which he would repeat in 1972.