Whitehall naturally became the chief staple of news. Whenever there
was a rumor that any thing important had happened or was about to
happen, people hastened thither to obtain intelligence from the
fountain head.
Macaulay.
3. The principal commodity of traffic in a market; a principal
commodity or production of a country or district; as, wheat, maize, and
cotton are great staples of the United States.
We should now say, Cotton is the great staple, that is, the
established merchandize, of Manchester.
Trench.