The fundamental purpose of the SGI-USA is the happiness of people and to contribute to peace, culture, and education based on the philosophy and ideals of the Buddhism of Nichiren.

Members of the SGI-USA practice the Buddhism of Nichiren for their personal happiness and for the development of a humane and peaceful society. A central aim of all SGI-USA activities is to promote humanistic dialogue based on Buddhist principles.

The SGI organization in the United States was officially established in 1960 by a handful of Japanese immigrants, members of the Soka Gakkai of Japan, which was founded in 1930. In less than 40 years, the American organization has grown to a multi-ethnic membership of 330,000, with members in every state and with more than 71 community centers around the country. The Soka Gakkai International (SGI) was founded in 1975 to link the efforts of members worldwide.

The Preamble to the Charter of the Soka Gakkai International states:

"We believe that Nichiren Daishonin's Buddhism, a humanistic philosophy of infinite respect for the sanctity of life and all-encompassing compassion, enables individuals to cultivate and bring forth their inherent wisdom and, nurturing the creativity of the human spirit, to surmount the difficulties and crises facing humankind and realize a society of peaceful and prosperous coexistence."