Castles offered great protection until the 1400s, when which weapons came into wide use?

Cassius Clay, playing himself, ends the career of boxer Mountain Rivera in which 1962 film? Castle Clinton in New York City was originally a fort, renamed in 1815 for which mayor? The British royal family's surname, adopted in 1917, comes from which castle? "Castle Richmond" (1860) is a novel by which author of "Barchester Towers"? Castor and Pollux are known as the twin sons of which god? Which children's author was born on March 2, 1904, a date now celebrated as Read Across America Day? Who wrote the play "Cat on a Hot Tin Roof"? What is the name of the portly patriarch in "Cat on a Hot Tin Roof"?