Why was the Liberian coast called the Grain Coast?

The Liberian coast earned the name Grain Coast due to the early trade of a specific spice known as grains of paradise (Aframomum melegueta), also referred to as Melegueta pepper.12

During the period of early Afro-Portuguese exploration and trade, these grains were highly sought after and considered as valuable as gold, making them the principal item of commerce in the region. The name specifically applied to the section of the western coast of the Gulf of Guinea extending approximately from Cape Mesurado to Cape Palmas.21