"It’s special. I remember three years ago trying to process being a three-time Olympian, and now being a four, I tried to enjoy each moment tonight. It was pretty exciting this morning just to feel the atmosphere, kind of get those first-race jitters out of the way. It was pretty loud for a prelims. Tonight, I just felt a lot more comfortable walking out on that pool deck. Felt like I could enjoy the crowd that was there and enjoy the atmosphere and just try to soak in every moment of the process, the process of getting to the Olympics," Ledecky said, according to Swimming World.

Ledecky, who became an Olympic gold medalist at age 15, is a world-record holder in three different events and the second swimmer to sweep the 200, 400 and 800 free at a single Olympics and one of only four swimmers to win three consecutive Olympic titles in the same event. The 27-year-old has captured 16 individual world titles and is the first to win six consecutive world titles.

At the men's 400 freestyle, 19-year-old Aaron Shackell became the first US swimmer to qualify for the Paris Olympics at trials, winning with a 3:45 time. Shackell took the lead from the beginning and fought off Tokyo Olympians in the event —runner-up Kieran Smith, fourth-place finisher Bobby Finke and eighth-place Jake Mitchell. 

"It was just a moment I’ve always dreamed of, watching previous Olympic trials. I was just soaking it all in," Shackell said emotionally at the podium. 

Gretchen Walsh also made waves at the trials, shattering the women’s 100-meter butterfly world record in her semifinal race with a 55:18 time in the two-lap event, breaking Swedish swimmer Sarah Sjöström’s 55:48 mark from 2016. Walsh also holds two junior world records and American records in several events. 

"I didn’t think I was going to do it tonight. I just knew that I wanted to go a best time, and now, here I am, world record holder. It’s actually insane," Walsh told USA Today.