One of the world's oldest sports, horse racing has been around since before Jesus Christ, when it flourished as a sport for kings and other nobles.
Today, times have changed and just about everyone can get into it. And many do, mainly because it is a major venue for legalized gambling.
With that said, the biggest part of the American horse racing scene is set to begin Saturday with the first leg of the Triple Crown, which will take place at Churchill Downs.
The 138th Kentucky Derby has seen some very famous horses race on its track, and this year will be no different.
But, this story isn't about this year's horses.
This story is about honoring horse racing's past.
Here's a look at the 10 greatest horses in American racing history.