September 1 - Sultan Hisamuddin Alam Shah, Sultan of Selangor and 2nd Yang di-Pertuan Agong of Malaysia, dies in office. He is replaced by Tuanku Syed Putra, Raja of Perlis. - Disgruntled railroad workers effectively halt operations of the Pennsylvania Railroad, marking the first shutdown in the company's history (the event lasts two days).

September 2 - The first elections of the Parliament of the Central Tibetan Administration are held. The Tibetan community observes this date as Democracy Day.

September 5 - 1960 Summer Olympic Games: Muhammad Ali wins the gold medal in light-heavyweight boxing. - The Congolese president, Joseph Kasavubu, fires Patrice Lumumba's entire government, and also places Lumumba under house arrest.

September 6 - William Hamilton Martin and Bernon F. Mitchell, two American cryptologists, announce their defection to the Soviet Union at a press conference in Moscow.

September 8 - In Huntsville, Alabama, U.S. President Dwight D. Eisenhower formally dedicates the Marshall Space Flight Center (which had been activated by NASA on July 1).

September 14 - Colonel Joseph Mobutu takes power in Republic of the Congo via a military coup. - The countries of Iran, Iraq, Kuwait, Saudi Arabia, and Venezuela form OPEC.

September 22 - Mali, the sole remaining member of the "Mali Federation" following the withdrawal of Senegal one month earlier, declares its full independence as the Republic of Mali.

September 26 - The leading candidates for President of the United States, Richard Nixon and John F. Kennedy, made the first televised debate.

September 30 - Television sitcom The Flintstones debuts on ABC. (source: Wikipedia)