You will enjoy Christopher Benfey's review of Peter Wood's Near Andersonville: Winslow Homer's Civil War (HUP 2010) in the most recent issue of NYROB.
The title of Wood's book (which was delivered as the Nathan I. Huggins lectures at Harvard) comes from Homer's painting of a young African American woman (presumably a slave) watching Confederate soldiers lead Union prisoners to the Andersonville prison in Georgia.
The review has a lot to say about interpretation of art and how much we should (or shouldn't) read into paintings. I hope you'll judge for yourself such issues as whether an African American man seated in a boat surrounded by sharks adrift in the gulf stream is a metaphor for the status and future of African Americans in the Jim Crow era -- or whether, as one of Wood's critics argues, Homer included the sharks in The Gulf Stream (1899) because "he thought it would make for a dramatic motif. It's that simple."