The bible for study of the African Slave trade. RI led the American side of the slave trade. Rum to Africa for slaves sold in the West Indies for sugar to make RI rum. Almost 70% of the slave trade in America originated in RI. Coughtry's meticulous research documents 100 years of the RI trade.
Unfortunately, the book is out of print and almost impossible to find. You can pick it up on Amazon for $200.