When Sarah Jarosz was nine years old, she met Sara Watkins at a festival. Both of them grew up with bluegrass music. Jarosz began playing the mandolin when she was ten, and Aoife O'Donovan noticed her when she was fifteen. O'Donovan said about Jarosz:
You were this amazing young person. You just had so much confidence and skill but you were never, like, "Look at me, I'm so good and I'm so young, heh heh heh." You always seemed like a peer.
Watkins, Jarosz and O'Donovan started collaborating at a workshop at the 2014 Telluride Bluegrass Festival, where they had been asked to sing together. They performed for the first time at the January 2015 Celtic Connections festival in Scotland, and continued to tour in Europe. In mid-2015, they wrote songs together for four days in Los Angeles, where Watkins lives. In December that year, they wrote for eight days at a farmhouse in Vermont with a hot tub and a wood-burning fireplace, surrounded by snow and near a barn with horses. The group began using the phrase "I'm with Her" as their tour name in early 2015. The phrase was later adopted by the 2016 Hillary Clinton presidential campaign, unrelated to the band.
The group covered John Hiatt's "Crossing Muddy Waters" in 2015, and released the single "Little Lies" in 2017, touring the US later that year. They recorded their debut album
See You Around at Real World Studios in Bath, Somerset, England, three weeks after they had written it. The album was co-produced by Ethan Johns and released on February 16, 2018. American singer-songwriter Gillian Welch wrote the album's last track "Hundred Miles"; the trio is credited with writing all other songs on the album. The group toured in the U.S. and in Europe in the first half of 2018.