Most modern dietary advice regards sugar as the devil, undesirable for health reasons. The Nineteenth Century had a better reason. The Atlantic slave trade began in the Sixteenth Century, but, as this animation shows, didn't pick up much speed until 1620 or so. By the Eighteenth Century, it had become a huge torrent, with hundreds of slave ships crossing the Atlantic every year.
Americans are most familiar with the slavery in the colonies and (mainly) in the southern States, but the overwhelming majority of slaves were destined for the Caribbean and Brazil to work the sugar plantations. The horrific conditions on these consumed human lives at such a rate that constant resupply from Africa was needed. The world's ravenous appetite for sugar had an enormous cost in blood and lives. By 1800, efforts at suppression of the slave trade had begun. It was banned in the US by 1807, and other nations passed laws which were fitfully enforced. By 1831 Brazil had outlawed the trade, and by 1850 started serious enforcement, expelling Portuguese slave traders. By 1820, the US had declared trans-Atlantic slave trading a capital offence, though only one man was ever executed for it: Nathaniel Gordon in 1862. Lincoln's refusal to commute his sentence apparently played a role in the Civil war.
The slave trade was a huge financial success for the nascent capitalist system, and a sober reminder that it workings are fundamentally amoral.