In 2002 at the AAHGS National Conference in Washington DC one of the presenters was a grad student from Howard University, J. Santiago Mauer - Ph.D. Student..his presentation was entitled Castas de Nacion: AFrican Ethnicity in Colombia, South America. He gave a listing of selected references most are in spanish..however two are in English:

Human Cargoes: The British Slave Trade to Spanish America, 1700-1739 Urbana: University of Illinois Press 1981 by Colin Palmer

The African Experience in Spanish America, 1502 to the present day.
Cambridge University Press, 1976 by Leslie B. Rout

"Carteagena was the one the largest slaving ports of the western hemisphere until the midway point of the seventeenth century. It along with the port of Vera Cruz, Mexico (then part of Nueve Espana -or new Spain) was designated as one of the two offical slaving ports for the Spanish controlled mainland. Only when the eastern Brazilian ports gave birth to their elevated volumes of human commerce in the 17th century was Cartagena overtaken as far as sheer numbers of imported Africans....Some authors estimate 4000 Africans arrived per year beginning in 1600......and that did not include the highly profitable contraband treade that had been in steady flux since the bottom half of the 16th centruy."

Selma