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 gas, discovered in 1774, got its name from the Greek words for "acid-forming"? Which component of the blood is abbreviated Hb? Which Baroque composer's initials were J.S.B.? Which composer, who died in 1827, reportedly said on his deathbed, "I shall hear in heaven"? 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? What is a concluding section added to a literary work, often revealing what later became of the characters? A Concord, New Hampshire, firm built which vehicles, whose fast drivers were nicknamed "jehus"?