What is associated with: 2 of browns sons were killed during the attack on the federal arsenal at this site october 16 1859?

Based on the clue '2 of 4 performing duos inducted into the rock and ...', what is the answer? What is referred to by '2 of 4 whigs'? Based on the clue '2 of 6 who married a widow', what is the answer? Based on the clue '2 of americas 3 manned space projects designed to ...', what is the answer? Based on the clue '2 of chiles juan fernandez islands are named for a...', what is the answer? Based on the clue '2 of englands finest landscape artists were jmw tu...', what is the answer? Based on the clue '2 of her dramas are watch on the rhine the childr...', what is the answer? Based on the clue '2 of his 4 sons served as state governors one in f...', what is the answer?