The United States women's 100 meter hurdles team made Olympic history Wednesday and two ACC stars -- Brianna Rollins and Kristi Castlin -- were right in the middle of the action.

Clemson's Rollins, Southern California's Nia Ali and Virginia Tech's Castlin finished 1-2-3 in the 100 meter hurdles, the first time in Olympic history a single country had swept the race.

Rollins finished with a time of 12:48, followed by Ali's 12:59 and Castlin's 12:61.

In the semifinals earlier in the day, Rollins placed first with a time of 12:47, while Castlin's 12:63 was second best. Ali's time of 12:65 was fourth.

For the pair of Atlantic Coast Conference alumnae, making the U.S. team may have been the hardest part of their mission.

In order to punch their tickets to the Games, Rollins and Castlin had to beat a U.S. Olympic Trials field that included nine of the top 10 100 meter hurdlers, a group that collectively had the 11 fastest times of the year heading into the Trials.

In July’s U.S. Trials final in Eugene, Oregon, Rollins’s time of 12.34 seconds was comfortably ahead of Castlin’s personal best of 12.50 and the 12.55 that Ali ran to earn a spot on the team. The Trials final marked the first time that seven women all ran sub-12.75 times in the same 100 meters hurdles race.

Castlin was appreciative of the entire field.

“You could pretty much equate us to a Dream Team,” she told teamusa.org. “It’s unfortunate all the ladies couldn’t go. If we had three different (people) up here (at the post-race press conference), they could do a good job (at the Olympic Games).

“This race was definitely just as or more competitive as the Olympic final,” Castlin continued. “We had 11 of the top times in the world. We can actually breathe now. We can go back to work to getting faster, even training for the world record. All three of us are capable of achieving that feat as well.”

A delighted Rollins echoed that sentiment.

“I look forward to competing with these ladies, and hopefully all three of us end up on the medal stand,” She told the Los Angeles Times.

The 24-year-old Rollins finished first in Tuesday’s heats with a time of 12.54 seconds. That was 14 one-hundredths ahead of the 12.68 that Castlin, 28, ran to advance to Wednesday night’s semifinal round. The University of Kentucky’s Jasmine Camacho-Quinn, running for Puerto Rico, came in third with a time of 12.70, and Ali advanced as well with a sixth place time of 12.76 seconds.

This is the first Olympics for both Rollins and Castlin, who don’t hide their affinity for one another.

“We’re all actually good friends,” Rollins told teamusa.org. “It’s something I actually envisioned before we got into the finals and I’m so grateful and so thankful that we all were able to come up on top.”

Their friendly rivalry has a history.

Both competed in the 2012 Olympic Trials, where Castlin's time of 12.93 just edged Rollins's 12.94. Rollins's time of 12.26 at the 2013 USA Track and Field Championships broke Gail Devers's 13-year-old American record time of 12.33, but at the 2014 Drake Relays, Castlin broke Rollins's 35-race undefeated streak.

So while Rollins and Castlin have both had each others' numbers over the years, they expected to be one another's chief rivals in Rio.

As Castlin said during the Trials, "I can’t remember the last time someone from another country finished in front of me."