Short answers, pulled from the story.
French card historian Thierry Depaulis traced the name to prospectors during the Klondike Gold Rush of 1896-99, who applied it to American vingt-un. He proposed the name came from the mineral zincblende, also called blackjack, which was often found near gold and silver deposits. He found no historical evidence for the popular myth of a special bonus payout for a hand containing an ace of spades and a black jack.
The oldest written reference appears in a story by Spanish author Miguel de Cervantes. His tale "Rinconete y Cortadillo," from Novelas Ejemplares, features card cheats in Seville who are skilled at veintiuno, Spanish for twenty-one. The story was written between 1601 and 1602, placing the game in Castile from at least the beginning of the 17th century.
Roger Baldwin, Wilbert Cantey, Herbert Maisel, and James McDermott published "The Optimum Strategy in Blackjack" in the Journal of the American Statistical Association in September 1956. Ed Thorp later used Baldwin's calculations to verify the basic strategy and published Beat the Dealer in 1963.
Under a standard ruleset, a single-deck game carries a house advantage of 0.16%, a double-deck game 0.46%, a four-deck game 0.60%, a six-deck game 0.64%, and an eight-deck game 0.66%. The increase in house edge is most dramatic when moving from one deck to two, and diminishes as more decks are added.
Card counting is legal. However, a casino may inform a card counter that they are no longer welcome to play blackjack, and may ban them from the property. In Nevada, using an external device to assist in card counting is illegal.
The Blackjack Hall of Fame is at the Barona Casino in San Diego. Seven members were inducted when it was established in 2002, with new inductees added each year. Members include Edward O. Thorp, Ken Uston, Arnold Snyder, and Stanford Wong.