New England has a more complex history of slavery and slave trading than many realize. . . .
.. . Almost all of colonial America’s slave ships originated in New England. Confronted with a landscape and climate unsuitable for large-scale commercial farming, New Englanders looked to the sea for their livelihood.
As a result, in the eighteenth century, New Englanders developed what came to be known as the Triangular Trade. Ships carried sugar and molasses from the plantation colonies of the Caribbean to New England where colonists distilled it into rum. Merchants then shipped this rum to Africa where it was exchanged for slaves, who were carried back to the Caribbean to produce more sugar.
—“New England and the African Slave Trade,” A Forgotten History: The Slave Trade and Slavery in New England, Choices Program, Brown University
Based on the excerpt, what was a MAIN reason that the colonists of New England engaged in the transatlantic slave trade?