'I Know That My Redeemer Liveth' comes from Handel's Messiah, written in 1742.
Antoine Watteau (1684 – 1721) and Alexandre-Évariste Fragonard (1780 - 1850) were French painters. Watteau in particular is credited with inventing theatrical bucolic scenes of the sort described here.
Studs Lonigan is the protagonist of the eponymous trilogy of novels by the American author James T Farrell (1904-1979). The trilogy examines Irish-American life in the South Side of Chicago, and was made into a film in 1960, starring Jack Nicholson.
Emily Dickinson was a nineteenth century American poet who led an eccentric, reclusive life in Amherst, Massachusetts. Dickinson's preoccupation with death was an important influence on Styron, especially while he was writing his first novel, Lie Down in Darkness (the novel Stingo appears to be writing in Sophie's Choice). Some critics suggest that Nathan's character in relation to Sophie is linked to that of Death in relation to the narrative voice in this poem.