Because they won the race war.
The FIDE Laws of Chess are clear on who is moving first:
BASIC RULES OF PLAY
Article 1: The nature and objectives of the game of chess
1.1 The game of chess is played between two opponents who move their pieces alternately on a square board called a ‘chessboard’. The player with the white pieces commences the game.
But it wasn't always like that. As late as the mid-to-late 19th century, the practice of White moving first had not yet become standard: it was either white or black that could start the game!
In annotations of some of the old games you'll see "adjustments" saying the players have been inverted (black<->white) to comply with today's requirements (especially computer programs that don't accept black beginnings.
The most known game is the "immortal game", played between Adolf Anderssen and Lionel Kieseritzky:
https://www.youtube.com/watch?v=mrWC-H3R8zQ
Yes, I know, it looks like white had the first move but...that's not true and you can check for yourself in the original book: The Chess Player, written by Bernard Horwitz and Joseph Kling, published by R.Hastings in London, 1852.
You'll see that Black was the one to start the game:
http://books.google.co.uk/books?id=jC0CAAAAYAAJ&dq=Anderssen&as_brr=1&pg=PA2&ci=63,663,856,696&source=bookclip&redir_esc=y#v=onepage&q=Anderssen&f=false
Chess historian Robert John McCrary writes that the earliest rule he has found requiring that White move first is Rule 9 given on page 126 of the New York, 1880 tournament book, which specified, "In each round the players shall have the first move alternately; in the first game it shall be determined by lot. The one having the move, in every case, is to play with the white pieces."
Prior to that, it had gradually become conventional, over a number of years, to have White move first in published analysis, and by about 1862 to have White move first in all published games. But it was evident that players could in many cases choose Black when they had the first move, even if the published game-score indicated that White had moved first.
In 1889 Wilhelm Steinitz, the first World Champion, wrote that "In all international and public Chess matches and tournaments ... it is the rule for the first player to have the white men". Emanuel Lasker, the second World Champion, stated unequivocally in Lasker's Manual of Chess (first published in 1927) that "White makes the first move".
But we are still left with the same annoying question: WHY?! We know now more or less when, but why does white move first?
Historically, chess has gone through a long metamorphosis, with the origins of white moving first being still unknown. There are a couple of opinions though, most of them circling around the same idea: racial politics on the first move.
Some argue that there are serious racial overtones in the game of chess : Psychiatrist Dr. Frances Cress-Welsing has used chess as a metaphor to describe racism within the context of her social "color-confrontation theory." While Dr. Welsing's theories have been long debated, there are some interesting truisms in her explanations.
Another opinion, which has no credible sources, would be:
"In medieval times black was thought to be a lucky colour. The white player was allowed to go first since the black player already had the advantage of the lucky colour."
As funny as it sounds, I cannot possibly think of black as being lucky...I could argue here the cats, the witches, all coming from the medieval times. Only ancient Chinese regarded black as the king of colors and honored black longer than any other color. But to draw a conclusion out of this, I think it's premature.
So where lies the truth? No one probably knows. Its just something you follow. Like Math. You just follow the rules...
If you want, think of it this way..
There is fire(white moving first), that starts the smoke(blacks response).
I'd make both sides grey and have them move simultaneously.
They're just colours. They're not meant to represent races.
@538,458 (brie)
This is what I learned, although with checkers, where red would be fire and black smoke. "Smoke comes before fire." "No, you can't have smoke without fire first!"
@previous (I)
I once sat down to play a game of chess with some guy at a coffee house. (actually he saw me playing and wanted a game) We set up the pieces, and I sat there waiting for him to make his first move. After five minutes or so I ask him if he's going to move. He looks at me, with all seriousness, and he says, "Smoke comes before fire." What. The. Actual. Fuck. I have had some really intense games with random coffee house people, but 75% of them are fucking looney and have no clue what they are doing. *I'm looking at
you people who pick up $RandomPawn and then remove $RandomPawn and say "en passant!" like you're Magnus fucking Carlsen scoring his latest strategic coup when you don't even know what the fuck "en passant" means.*
(Edited 3 minutes later.)
@538,549 (K)
see
@previous (L)
It is a relatively minor rule in chess that casual players are constantly misinterpreting.
@previous (J)
I just try to get rid of all the pawns so I can use the rook cause that's my favorite piece.
@538,561 (J)
I love the blank look you get when trying the move down the pub.