By Nick Mulvenney

RIO DE JANEIRO (Reuters) - Like many black American women, Brianna Rollins, Nia Ali and Kristi Castlin have faced a good few hurdles of the metaphorical kind in their lives.

On Wednesday at the Rio Olympics, though, they successfully traversed 10 very physical barriers - 33 inches of polycarbonate and metal - to give the United States gold, silver and bronze in the 100 meters hurdles.

It was the first ever sweep of the podium in the Olympic high hurdles by women of one nation and illustrated the depth the United States have in an event where just making it through the national trials is an achievement in itself.

With world record holder Kendra Harrison and 2008 Olympic champion Dawn Harper failing to make the cut, the trio who did get their tickets to Rio decided to work together.

Gold medalist Rollins described it a "sisterhood", while Castlin added very much a 2016 twist in a phrase more often seen on social media with a hashtag in front of it.

"I think that it's just very good to be a part of this whole black girl magic movement," she said.

"We actually came into this not as individuals but as a team. We work together, we pray together and that is how we got this job done.

"It feels good to definitely be history-makers, trend-setters, moms, daughters, really just overcoming and just doing a great job and representing our country well."

Castlin dedicated her bronze medal to victims of gun crime, a cause very close to her heart after her father was murdered in a botched attempt to rob a hotel where he was the manager.

"Losing my father at the age of 12 to gun violence, I've overcome so much," said the 28-year-old. "I want to connect more with young people that have been victims of gun violence.

"I feel, when I was young, I definitely had a lot of good guidance but sometimes I didn't have someone of my age that I really could talk too."

Her fellow medalists have also had to deal with major challenges in their early lives - Ali when her father killed himself in a murder-suicide and Rollins when her father was sent to prison.

Ali's most recent challenge, though, was one faced by female athletes all over the world, getting back into world class condition after having a child.

Fifteen-month-old Titus now has two Olympic silver medalist parents as his father Michael Tinsley finished second in the 400 meters hurdles at the London Olympics.

"I knew it was going to be a difficult road back. I see mothers struggle to get their body back," said Ali.

"I'm happy that I was able to come back and come back so quickly.

"I have my son here with me and he plays a major role."

(Editing by Sudipto Ganguly)