The word “yam” comes from the the West Africa word “nyam,” which means “to eat”, and as a noun it means “food” (Abarca 37). The importance of the root vegetable can not be overstated, as it is a staple food in Africa due to its nutritional value and its ability to grow without much tending.
Europeans who traveled to Africa to enslave people would journey inland on “slave raids” and would buy various types of yams being grown and sold within the “yam belt”, an area that stretches from the Bandama River (modern-day Ivory Coast) to the eastern Cameroon Mountains (Behrendt 65). The yams bought during these trips (both yellow and white yams) provided sustenance for those enslaved as they started their perilous journey across the Atlantic Ocean.
In order for the captians of the slave ships to ensure that they made the most profit from their captured slaves, they needed to make sure that the slaves would survive the Middle Passage (the Middle Passage refers to the journey by ship across the Atlantic Ocean, the end result for many being different ports in the Caribbean). To ensure their slaves survived the journey, slave raids occured during the peak of the yam growing season in West Africa, the hope being that the yams would provided enough sustinance to keep the slaves alive during their gruling months at sea (Behrendt 65).
Graph from "Ecology, Seasonality, and the Slave Trade"
Slaves taken in the "preharvest" months were more likely to be malnourished and therefore more likely to die during the voyage. Infact, data from various slave trades indicate that Middle Passage slave deaths were based on the yam supplies of the vessels.
Image of the Middle Passage, with a focus on movement between Africa and the Caribbean
According to data provided by slaver traders, ships who sailed and traded between January and June, when yams provisions we low due to being out of season, lost 26% of their human cargo, which was a loss of revenue for the slave traders, and loss of life for many enslaved people on these ships (Behrendt 59). Some of the enslaved people who were able to survive the Middle Passage, were bought when they arrived in the Caribbean to work on plantations, farming sugar cane.