I beieve you mean Harrison's Hoss Race, if so then President Benjamin Harrison announced that the government would open 1.9 million acres of Indian Territory to settlement and Boomers, Sooners, and settlers all wanted to stake their claims.
The rider of a horse in a race is called a Jockey.
A steward.
A person who rides horses (mainly thoroughbreds) is called a Jockey
Not that I've heard of.
A horse jockey's mount is called a horse. The mount refers to the horse that the jockey rides during a race or competition.
yes
Spectate means to attend an event (like a horse race), to become a spectator.
This is the show horse. Win, place and show.
it is called a relay race
The common sobriquet for Thoroughbred horse racing is called The Sport of Kings.
Your horse needs to be fully grown, and medically well but different horse competitions allow different ages. Look at the website for the race or ask someone that is an expert on that particular race/event/competition.
A stallion like the rest