Wikipedia
Triangular trade or triangle trade is a historical term indicating trade among three ports or regions. Triangular trade usually evolves when a region has export commodities that are not required in the region from which its major imports come. Triangular trade thus provides a method for rectifying trade imbalances between the above regions.
The particular routes were historically also shaped by the powerful influence of winds and currents during the age of sail. For example, from the main trading nations of Western Europe it was much easier to sail westwards after first going south of 30 N latitude and reaching the so-called " trade winds"; thus arriving in the Caribbean rather than going straight west to the North American mainland. Returning from North America, it is easiest to follow the Gulf Stream in a northeasterly direction using the westerlies. A similar triangle to this, called the volta do mar was already being used by the Portuguese, before Christopher Columbus' voyage, to sail to the Canary Islands and the Azores. Columbus simply expanded the triangle outwards, and his route became the main way for Europeans to reach, and return from, the Americas.
Usage examples of "triangular trade".
A large part of his fortune he gained in a triangular trade among the worlds of Simoom, Yarkona and Catava.
As for myself, I came here first for a spot of lobbying for the 'continuous voyage' rule, so that goods on the triangular trade would not pay two duties.
And his son, Jeremiah Cabwell, engaged in the harrowing triangular trade, risking his all, by Thoreau, in the dangers of trading sugar, for rum, for slaves, helping thousands of African immigrants come to our great country.
The US too would purchase raw materials from the former colonies, thus reconstructing the triangular trade patterns whereby the industrial societies purchase US manufacturing exports by earning dollars from raw materials exports by their traditional colonies.