Complex sentence: In 1962 Adam received the Presidential Medal of Freedom from President John F. Kennedy on the day the President asked him to retire; it had been discovered by the public that he is an African-American.
Split into simpler sentences: In 1962 Adam received the Presidential Medal of Freedom from President John F. Kennedy on the day the President asked him to retire. The reason why he was asked to retire was that it had been discovered by the public that he is an African-American.