Who was known as the 'Angel of the Battlefield' during the U.S. Civil War?

Clara Barton

Which city is the primary setting of "Ferris Bueller's Day Off"? What smartphone game requires players to swipe matching numbers to create a 2048 tile? What reptile can detach its tail to escape predators? Which blood vessels carry blood toward the heart? In what year did the Great Fire of London occur?