September 11 is now famously known as the Universal Brotherhood Day. It is because that day Swami Vivekananda addressed the delegates at the Parliament of World Religions at Chicago as 'Sisters and Brothers'. He addressed the Parliament as the representative of the Hindus all over the world. To the Hindu, all men and women, irrespective of caste, creed or religion are brothers and sisters. It was for the first time in the history of the world that such a beautiful concept was expressed. It is in remembrance of this that this day is called Universal Brotherhood Day.