The TED (technology, entertainment, and design) conferences were established in 1984 by Richard Saul Wurman, a graphic designer, and Harry Marks. The first ever talk was held in Monterey, California in February 1984 and included a viewing of an early Sony CD and a Macintosh computer. You can see an example talk from the first event here (Nicholas Negroponte talking about the future).
Regular TED talks were not established until 1990 - this was because, even though the first talk was a great success, it didn't actually make any money and it was several years before Marks and Wurman could afford to put on another event. The same venue was chosen (Fremont Street in Monterey) and the talks have been held there ever since.
Nowadays TED is much more of a global event - it has prizes and has created new organizations, and the focus is no longer just on science but includes philosophy and the arts too. It also has a huge audience thanks to the free podcasts which are released of the best talks.
You can read more about the history of TED here.