Black man with white child and dog

This aptly called, "Black man with white child and dog" ca. 1890 from George Eastman House Collection.  The picture intrigues me, what an odd combination.  The dog in this picture is way bigger than the child.  The black man is very well dressed, the child seems comfortable with him, what can the story behind this picture be?  Care to take any guesses??  Be sure to visit http://sepiasaturday.blogspot.com/ for many more interesting contributions this week and every week.