The Wealth of Nations by Part 4 Chapter 7 Page 227

trade are not altogether the same. Monopoly is the great engine of both; but it is a different sort of monopoly. Monopoly of one kind or another, indeed, seems to be the sole engine of the mercantile system.

In the trade to America every nation endeavours to engross as much as possible the whole market of its own colonies by fairly excluding all other nations from any direct trade to them. During the greater part of the sixteenth century, the Portuguese endeavoured to manage the trade to the East Indies in the same manner, by claiming the sole right of sailing in the Indian seas, on account of the merit of having first found out the road to them. The Dutch still continue to exclude all other European nations from any direct trade to their spice islands.

Monopolies of this kind are