I think it was invented by the English Army Officers in India, more to pass the time than anything. I think there may have been earlier versions but that is where the present version originated.

check this out:

Oh! How anal am I! Following centuries of Billiards dominated by England and France, during the 19th century a third country became obsessed with the sport of cues and balls. Billiard tables had been appearing in all the colonies from the 1600s but Americans were particularly keen. As with other aspects of American life, Billiards culture became a mish-mash of the cultures of the immigrant populations. Americans played early Port and King Billiards, held English Billiards competitions, indulged in Pin Billiards from Italy and, in contrast to Britain and its empire, imported Carambole tables without pockets from France. American Fifteen-Ball Pool or "Sixty-one Pool" is the predecessor of all modern 'Pocket Billiards' games. It was played with 15 object balls as in the English game Pyramid, but crucially, the balls are numbered 1 through 15. For sinking a ball, the player received a number of points equal to the value of the ball. The sum of the ball values in a rack is 120, so the first player who received more than half the total, or 61 , was the winner. The word "pool" means a collective bet and became a term for the game when it began to be played in 19th century "pool rooms" which were then places for betting on horse.races. Continuous Pool replaced Fifteen-Ball Pool as the championship game when, in 1888, it was thought more fair to count the number of balls pocketed by a player and not their numerical value . Thus, the player who sank the last ball of a rack would break the next rack and his point total would be kept "continuously" from one rack to the next. Eight-Ball Pool was invented shortly after 1900 and is one of the most widely played of all Billiards games today. Straight Pool followed in 1910. Also known as 14.1 Continuous. The object is to pot 14 of the 15 balls one after the other and in any order leaving just one ball whereupon all the others are racked up and the break continues. One point is scored for each ball potted. Nine-Ball Pool seems to have developed around 1920. This game is now more popular in Europe particularly in Sweden and Germany. Balls one to nine are racked up in a diamond with the nine ball in the middle and the one ball nearest the baulk line. Each shot must always hit the lowest numbered ball on the table first and then pocket a ball or make two balls reach a cushion. If this isn't achieved, it is a foul and the balls are re-racked for the opponent to play.