"I was definitely nervous," Walsh said. "There were a lot of what-ifs. Coming off breaking the world record, I was thinking, 'Do I need to do that again just to make the team? What if I get third? What's that even even going to look like?'"
No worries. She's heading to Paris.
So is Carson Foster. He made up for the disappointment of 2021, when he just missed out on the Olympics, with a victory in the men's 400 individual medley.
And 30-year-old Nic Fink, whose wife is expecting a child, made it quite a Father's Day — or should that be Expectant Father's Day? — by winning the 100 breaststroke on the second night of the trials.
Looking into the stands at massive Lucas Oil Stadium, he spotted Melanie Margolis Fink — herself a swimming gold medalist at the 2016 Rio Games — and made a rocking motion.
Clearly, Nic Fink's mind was on more than just a gold of his own. The couple's first child, a boy, is due in mid-September.
"It's one of those things that doesn't really make sense to me," Fink said. "I feel like I haven't earned it yet. But the next (Father's Day) will feel like one for sure after diapers and late nights and stuff like that."
Facing three medalists from the Tokyo Games, Walsh knew she had her work cut out for her — even after setting a world record in the semifinals with a time of 55.18 that broke the mark held by Sweden's Sarah Sjöström since the 2016 Rio de Janeiro Olympics.
Following the same strategy, Walsh went out strong again in the final and was under her world-record pace at the turn.
Then, it was a matter of hanging on for the 21-year-old native of Nashville, Tennessee, who swims for the University of Virginia.
She finished with the second-fastest time in history, while Torri Huske grabbed the second Olympic spot with a time of 55.52 that made her the third-fastest woman in swimming history.
"I couldn't ask for a better start to the meet," Walsh said.
Regan Smith became the fourth-fastest female ever at 55.62 — but the third-place showing wasn't enough to get her to Paris on the powerhouse American team. She'll have more chances later in the meet to claim her spot.
The first final of the night produced another first-time Olympian when Foster knocked off Tokyo gold medalist Chase Kalisz.
But Kalisz should get a chance to defend his gold in Paris, taking the runner-up spot to claim the expected second American slot.
Jay Litherland, the 400 IM silver medalist in Tokyo, missed out on his third Olympics with a third-place showing.
The 22-year-old Foster, a native of Cincinnati who swan collegiately at Texas, led the entire race to finish in 4 minutes, 7.64 seconds.
He appeared on the verge of tears as Kalisz reached over the lane rope to give him a hug, knowing how much this meant to the winner.
At the 2021 trials in Omaha, Nebraska, Foster was the top seed coming out of the preliminaries, only to get chased down by both Kalisz and Litherland in the final.
The third-place finish cost Foster a trip to the Tokyo Games. When the Americans went 1-2 at the Olympics, the missed opportunity hurt even more.
"As much as I've grown, there was still a fear because of what happened three years ago," Foster conceded.
But, as he stepped to the block, with Kalisz on one side and Litherland on the other, a newfound confidence swept over Foster.
"I've struggled to stay in my lane in the past," he said, speaking metaphorically. "The first thing that would go wrong, it was lights out for me. I've battled those inner negative voices. But tonight was different. I stayed in my own lane. I think I was smiling the whole last 50."
Kalisz closed to within a tenth of a second on the breaststroke leg, but the 30-year-old simply didn't have enough in the tank to keep up with the younger Foster. The winner pulled away on the freestyle, with Kalisz touching in 4:09.39.
Litherland faded at the end for a time of 4:12.34.
Fink, who balances swimming with a 40 hour-a-week job, with parenthood soon to come, will be heading to his second Olympics after touching first in 59.08. He held off Charlie Swanson, who secured the expected second spot for Paris in 59.16.
"That's a win for me," Fink said, "but it's really a win for everybody in my life."
A life that will soon have a new addition.