Who was the first negro convert?
"Now an angel of the Lord spoke to Philip, saying, "Arise and go toward the south along the road which goes down from Jerusalem to Gaza." This is desert. So he arose and went. And behold, a man of Ethiopia, a eunuch of great authority under Candace the queen of the Ethiopians, who had charge of all her treasury, and had come to Jerusalem to worship, was returning. And sitting in his chariot, he was reading Isaiah the prophet. ... Now as they went down the road, they came to some water. And the eunuch said, "See, here is water. What hinders me from being baptized?" Then Philip said, "If you believe with all your heart, you may." And he answered and said, "I believe that Jesus Christ is the Son of God." So he commanded the chariot to stand still. And both Philip and the eunuch went down into the water, and he baptized him" (Acts 8:26-28, 36-38).
Ethiopia is a country just south of Egypt. People of that nation tend to be dark in skin color, so it is assumed that the Queen's treasurer would be as well.