Today, Deshawn Parker is perhaps the most successful of the few black jockeys competing in the states, boasting more than 4,000 career victories.

The 42-year-old, who won the most U.S. events in 2010 and 2011, entered the sport after his father worked as a racing official.

"Black people aren't on the track like they used to be," he said. "If you don't have someone in your family who's in the business, you don't have a reason to start racing."

Parker, the 54th-ranked jockey of all time, says racing is now dominated by Latinos.

Terry Meyock, national manager of the Jockey's Guild, agreed, estimating that 60% of jockeys in the U.S. are Latinos.

Of the current top-10 highest earning jockeys, nine are from South America.

"From black to Irish to Latino, jockeys in America tend to mirror immigration," Drape said.

"The conditions are the same as 200 years ago -- the best jockeys tend to be from rural countries, they grow up around horses, it's tradition and it's a family business."

For Parker, jockeys like Murphy and Winkfield didn't just change the face of racing -- they paved the way for generations of black American sports stars.

"They got black athletes in the door," he said. "It's an honor to be ranked among them."