The exact origin of the game isn't known, but the first games with paper cards were played in China, around 900 A.D., and these were probably the first known cards.
Islamic culture left its influence in early cards design, and after they were brought to Italy and Spain, they got the first Kings and Queens pattern.
The deck we still use today, so called 'French pack', appeared somewhere in the 1600's, and the game known as Blackjack appeared around 1700's.
Supposedly it got the name by special bonus combination of that time - the Ace and the Jack of Spades.
The first games we can find some similarities with the game of blackjack were played in France. One of them was called 'Chemin de Fer', or 'the way of iron', and the other 'French Ferme'. Later on, the new game was developed, named 'Vingt et un', or literally 21.
Of course, there are some differences between this game and today's Blackjack.
In the original game, all the cards had their real value, and in today's Blackjack all faced cards have the value of 10.
The game we got the term 'busted' from was called 'seven and a half', and that was the number of points to collect.
The Spanish game 'One and Thirty' seems to be the origin for the Blackjack rules known today, except they had to aim to get 31 points instead of 21. Payouts were bigger those days, up to 10:1.
Thorp's book 'Fortune's Formula' was one of the first published techniques for beating the game. He explained in details how you could get some advantages by counting cards.
Thorp was one of those people who were more interested in the logic behind the game, although they were players, also. Together with his friend Kimmel, he went to Reno and proved his formula with some nice financial results.
Ken Uston also counted cards, but in Las Vegas. With his friend Taft he even made a device to help them win large sums of money.
Lots of people are still trying to be as good as possible in card counting. The main reason probably is the money, but there is also an element of a pure pleasure of beating the game.