It is a big business and a fat tax source, and these facts have some profound implications for the sport itself. They have meant a new era for U.S. racing - an era those in the sport see as one of revolution.
It is, in cat, only the second revolution in the sport since that first chronicled race in England eight hundred years ago.
The first set of changes began in the seventeenth and early eighteenth centuries. In the reigns of James I, Charles II, and Queen Anne.
Racing was organized with royal patronage; in time the thoroughbred was produced by breeding the fastest to the fastest, and the wager between competing owners was formalized in the stake race.
Breeding, racing, and betting were thus formally joined into the structure of a vast and intricate game.
The second great change began to materialize in the U.S. decades ago, when the tracks and the states in large numbers first took a share of the 'handle' - i.e., the bet's overall expense.
It would be an oversimplification to say that this in itself made horse racing an entertainment business, but the business aspect emerged much more sharply when racing became an impressive instrument for raising state tax revenue.
Racing today may be thought of as a private industry operating under state regulation. Horsemen often talk as if the feared the business would swallow the sport and the taxing agent would swallow both.
Thus far, racing has managed to keep its essential charm, and indeed it has a broader base in participation and a larger public than it had in earlier times.
And yet, paradoxically, the vast expansion of interest in racing, and in the handle, threatens some of the traditions on which this most traditional of sports has rested.
The raw figures of thoroughbred racing's recent expansion are impressive. The attendance, estimated at 8,500,000 in 1940, rose to 33,543,900 in 1959.
In the same period, the handle soared from about $400 million to $2,439,168,200. The twenty-four racing states collected $186,579,600 in racing taxes in 1959, and this figure represents roughly half of the total 'take,' for example, half of the percentage that is taken out of the betting pool before the winners are paid off.
In the Eastcoast, the take, however, varies from 12 percent in Delaware to 17 percent in Maine, and the state's share of the take varies, too.
The rest goes to the tracks, which are ordinarily private corporations, although some of them are set up on a nonprofit basis.