At age 26, Jonathan Dayton of New Jersey was the youngest signer of which 1787 document?

In Dumas's novel, which young man set out from Gascony in 1625 at age 18 to join the King's Musketeers? At age 19 in 1892, which Russian pianist wrote his Prelude in C-sharp minor, which helped launch his career? At age 19 in 1984, who founded PC's Limited, selling upgraded IBM-compatible computers from his dorm room? At age 25, who won the $25,000 Orteig Prize for the first solo nonstop flight between New York and Paris? At age 31 in 1977, who became mayor of Cleveland? In 1998, which former basketball star briefly hosted a late-night talk show called "The Magic Hour"? At age 40 in 1781, which American traitor moved to London but was denied further military service? At age 40, which singer won three Grammys for "Nick of Time," including Album of the Year for 1989?