Why did sugar, more than almost any other crop, run on slavery?

Because sugar demanded more labour, capital and expertise than tobacco or even cotton, and because the labour was taken by force. Sugar is complicated and time-consuming to grow and process, and that aspect led to the use of slavery. Cane had to be harvested by hand, and the sucrose inside needed to be harvested quickly so it would not spoil. Each step of processing was labour-intensive and required technical knowledge and skill.

The people who did that work changed as the plantations spread. The labour force at first included European indentured servants and local Native American and African enslaved people. European diseases such as smallpox, and African ones such as malaria and yellow fever, soon reduced the numbers of local Native Americans. Europeans were also very susceptible to malaria and yellow fever, and the supply of indentured servants was limited. African enslaved people became the primary labour force on sugar plantations, helped by the transatlantic slave trading systems along the African coast.

Scale made it worse. Sugar was a cash crop with economies of scale, so it was most efficiently grown on large plantations with many workers. In 1680 the median plantation in Barbados held about 60 slaves. By 1832 the median in Jamaica was about 150, and nearly one in four bondsmen lived on units with at least 250.

The Caribbean colonies produced up to ninety percent of the sugar western Europeans consumed. Enslaved workers resisted: in Louisiana in 1811, as many as 500 burned sugar plantations as they marched on New Orleans. In 1838 more than half a million people in the Caribbean were emancipated from slavery.