The Wealth of Nations by Part 4 Chapter 7 Page 69

Sugar was originally an enumerated commodity which could be exported only to Great Britain.

But in 1731, upon a representation of the sugar-planters, its exportation was permitted to all parts of the world. The restrictions, however, with which this liberty was granted, joined to the high price of sugar in Great Britain, have rendered it, in a great measure, ineffectual. Great Britain and her colonies still continue to be almost the sole market for all the sugar produced in the British plantations. Their consumption increases so fast that, though in consequence of the increasing improvement of Jamaica, as well as of the Ceded Islands, the importation of sugar has increased very greatly within these twenty years, the exportation to foreign countries is said to be not much greater than before.