In "The Negro's Complaint," Cowper links the suffering of black slaves to racism and profit.
FORCED from home and all its pleasures / Afric's coast I left forlorn, /To increase a stranger's treasures/
Later in the poem, he tells us how the three are connected:
Think how many backs have smarted/ For the sweets your cane affords.
Here, Cowper is referring to the sugar trade. The Spanish and the Portuguese were the first to begin sugar cultivation on Atlantic islands. The sugar was then exported to European countries, where citizens eventually developed a passion for this addictive product. In fact, the sugar crop was then referred to as white gold, for the tremendous profits it brought to those who cultivated the crop. In the poem, Cowper refers to the slaves who worked on sugar plantations as "slaves of gold." Eventually, both the British and the French imported black slaves to work on sugar plantations in the American colonies.
The sugar trade was so profitable that many sugar barons enjoyed great wealth from St.Kitt's to Jamaica. By the 19th century, sugar accounted for a third of the English economy; most of the sugar plantations were situated in Brazil and the Caribbean islands. Sugar is an extremely labor-intensive crop; it is back-breaking work. Once cut, the canes must be processed immediately. Slaves worked in the sugar fields and in enormous boiling houses. The risk of injury from the sharp, spiky canes added to the great misery in the terrible heat of the boiling houses. Yet the profits were enormous. Unprincipled slave owners sustained this profit-machine through beatings and floggings.
...knotted scourges,/ Matches, blood-extorting screws,/ Are the means that duty urges/ Agents of his will to use?
The slave in Cowper's poem asserts that it is unconscionable that the color of his skin alone has earned him this terrible suffering. He begs slave owners to find some other reason to justify their cruelty other than their racism:
Deem our nation brutes no longer,
Till some reason ye shall find
Worthier of regard and stronger
Than the colour of our kind.
Hope this helps! Please refer to the links below to read more about the sugar trade and life on sugar plantations between the 16th and the 19th centuries.