From my understanding my greatgrandfather was a slave bought by the french and was taken to Puerto Rico. They gave him the name Lazu. And his nick name was El Congo. this name was given to him by the french. I am guessing they had something to do with the sugar cane buisiness at the time. Because then my grandfather was one of the heads at the sugar cane industries in Yabbucoa, Puerto Rico. His name was Juan Maria Lazu. My father was also named after his father. All three of them were all known by the nickname El Congo. Our family still resides in Yabbucoa, Puerto Rico. My father came to Chicago and died in Chicago in 1972. There are a few members of our family that reside in Chicago as well.
So my understanding the name was given to us by the French, but my ancestors were from Africa. If you want anymore information and if I can be of any help please contact me. Hope the information I have provided has helped somewhat.