Swami Vivekananda (12 January 1863 – 4 July 1902), born Narendra Nath Datta (Bengali: [nɔrend̪ro nat̪ʰ d̪ɔt̪t̪o]), was an Indian Hindu monk and chief disciple of the 19th-century saint Ramakrishna. He was a key figure in the introduction of the Indian philosophies of Vedanta and Yoga to the Western world and is credited with raising interfaith awareness, bringing Hinduism to the status of a major world religion during the late 19th century. He was a major force in the revival of Hinduism in India, and contributed to the concept of nationalism in colonial India. Vivekananda founded the Ramakrishna Math and the Ramakrishna Mission. He is perhaps best known for his speech which began, "Sisters and brothers of America ...," in which he introduced Hinduism at the Parliament of the World's Religions in Chicago in 1893.
Born into an aristocratic Bengali family of Calcutta, Vivekananda was inclined towards spirituality. He was influenced by his guru, Ramakrishna, from whom he learnt that all living beings were an embodiment of the divine self; therefore, service to God could be rendered by service to mankind. After Ramakrishna's death, Vivekananda toured the Indian subcontinent extensively and acquired first-hand knowledge of the conditions prevailing in British India. He later travelled to the United States, representing India at the 1893 Parliament of the World Religions. Vivekananda conducted hundreds of public and private lectures and classes, disseminating tenets of Hindu philosophy in the United States, England and Europe. In India, Vivekananda is regarded as a patriotic saint and his birthday is celebrated there as National Youth Day.
Example via www.ramdass.org: Swami Vivekananda
Example via www.mindpodnetwork.com: Swami Vivekananda on the Vedanta Philosophy