Why was call to post used for horse racing?

The "call to post" is a traditional signal used in horse racing to indicate that the horses should be taken to the starting gate. Originating in the 19th century, it serves to alert jockeys, trainers, and spectators that the race is about to begin. The phrase is often accompanied by a bugle call, creating a ceremonial atmosphere and helping to build excitement for the event. This practice reinforces the formal structure of horse racing as a competitive sport.