Of all British markets the American was the most valuable; but next to the American market was that of the West Indies. In some respects the West Indian was of the two the better worth preserving. From head to foot the planters and their half-million negroes were always clad in cottons or linens made by the clothiers of Yorkshire, Wiltshire, or Belfast. Every cask and hoop, every implement and utensil, was supplied from the British Islands. The sailing of a West Indian convoy was “an epoch in the diary of every shop and warehouse throughout the Kingdom.”[232] The West Indian colonies employed, including the fisheries, above a thousand sail of shipping and twenty-five thousand seamen. While America might, and one day certainly would, manufacture for herself, the West Indies could not even dream of it; there the only profitable or practicable industry was cultivation of the soil, and the chief article of cultivation was the sugar-cane. Rival industries to those of Great Britain were impossible; the only danger that threatened British control was the loss of naval supremacy or the revolt of the negroes. A great majority of British electors would certainly have felt no hesitation in deciding, as between the markets of the United States and of the West Indies, that if a choice must be made, good policy required the government to save at all hazards the West Indies. Both as a permanent market for manufactures and as a steady support for shipping, the West Indian commerce held the first place in British interests. This fact needed to be taken into account by the United States government before relying with certainty on the extent to which Great Britain could be controlled by the interests involved in the American trade. At the most critical moment all Jefferson’s calculations might be upset by the growth of a conviction in England that the colonial system was in serious danger; and to make this chance stronger, another anxiety was so closely connected with it as to cause incessant alarm in the British mind.