What is a concluding section added to a literary work, often revealing what later became of the characters?

Which composer, who died in 1827, reportedly said on his deathbed, "I shall hear in heaven"? A compromise allowed Maine's admission to the Union in 1820 as a free state and which state in 1821 as a slave state? Which is the oldest campus of the University of California? Which word means a con game or swindle, as well as the police squad that breaks it up? A Concord, New Hampshire, firm built which vehicles, whose fast drivers were nicknamed "jehus"? A condensed version of which author's "Roots" appeared in Reader's Digest in 1974? Who wrote the novel "A Confederacy of Dunces"? Which 1850s song, sung by Confederate troops, became a No. 1 hit for Mitch Miller in 1955?