The band formerly included lead vocalists Jonny Craig, Kurt Travis, and Tilian Pearson, and the lineup has changed numerous times since their inception.

Craig and guitarist Sean O'Sullivan left the group and were replaced by Kurt Travis and Zachary Garren, respectively.

In 2010, Jonny Craig, Jon Mess and Eric Lodge returned to the band and recorded their fourth studio album, Downtown Battle Mountain II (2011).

Craig and Lodge departed from the group the following year, which led to bassist Tim Feerick, guitarist Josh Benton, and former Tides of Man vocalist Tilian Pearson joining the band.

In 2020, they released their ninth studio album, Afterburner in April, which placed at number 14 on the Billboard 200, and Tree City Sessions 2 in December.

Bassist Tim Feerick died in 2022, prior to the release of the band's tenth album, Jackpot Juicer, leading to Sianvar and Royal Coda guitarist Sergio Medina taking over on live bass duties.

In 2005, they self-released their debut extended play (EP), Whatever I Say Is Royal Ocean, which was subsequently re-released on November 14, 2006, on Rise Records.

[5] Their debut studio album, Downtown Battle Mountain, produced by Kris Crummett, was released on May 15, 2007, on Rise Records.

The band toured with American post-hardcore groups Alesana, A Day To Remember and Pierce the Veil in support of the album.

Other singers that auditioned included Kellin Quinn of Sleeping with Sirens, Matt Geise of Lower Definition, and Thomas Dutton.

[11] Prior to the release of the album, but following its recording sessions, two original members, unclean vocalist Jon Mess and bassist Eric Lodge, departed from the band.

The group filmed a music video for the song "Me and Zoloft Get Along Just Fine", with director Robby Starbuck, which was released November 18, 2008.

Bassist Jason Ellis appears on Happiness, however left the group before its release, subsequently being replaced by Tim Feerick as a touring member.

AllMusic gave a mixed review of the album, writing, "Happiness bristles with the kind of overachiever eclecticism that's as impressive as it is divisive," but that two songs were marred by the "nasally realm of high school emo," leaving the listener unsatisfied with the experience.

Shortly after, Garren met drummer Ben Rosett and formed the math rock trio Strawberry Girls, now signed to Tragic Hero Records.

In an April 2011 interview with Mind Equals Blown, drummer Matt Mingus stated the band plans to release another album with the current, reunited lineup.

[21] Tilian Pearson, formerly of Tides of Man, was asked to replace Craig as clean vocalist during the making of his solo album, Material Me (2013).

On October 29, 2014, producer Kris Crummett announced that recording sessions for the band's sixth studio album were completed.

[29] They also performed at the Extreme Thing Sports & Music Festival in Las Vegas, Nevada on April 2, 2016, with other bands such as Saosin, the Story So Far, the Maine, Mayday Parade, among several others.

On May 10, 2016, the band announced the U.K. leg of their 10th anniversary tour that included vocalists Tilian Pearson, Kurt Travis, and Jonny Craig.

On October 4, 2017, the band announced a U.S. tour, consisting of the group performing their seventh studio album Mothership in its entirety through December, with support from Polyphia, Icarus the Owl, and Wolf & Bear.

On February 26, 2021, guitarist Will Swan confirmed that the band were writing their tenth studio album and are scheduled to begin recording in the summer.

The 21-date North American stretch of live shows excluded vocalist Tilian Pearson, with Andrew Wells and former frontman Kurt Travis sharing clean vocal duties instead.

[65][66] On May 16, 2023, the band announced The Jackpot Juicer Tour with support from SiM, Rain City Drive, and Within Destruction as well as Swanfest 2023 taking place in Philadelphia, PA with Stolas, Dwellings, Periphery, Body Thief, Saosin, and Set It Off also joining the festival.

[67] On August 24, 2023, the band released a new song called “The Ghost of Billy Royalton” as well as a music video made by guitarist Will Swan for the late Tim Feerick.

Exactly 2 months later, the band released another new song called "War Machine" as well as a music video directed by Mount Emult.

[68] On April 15, 2024, the band announced the departure of clean vocalist Tilian Pearson via Instagram, citing creative differences and their goals no longer aligning as the reason.

[77] Their 2011 release Downtown Battle Mountain II is said to feature “the same structuring as The Mars Volta album The Bedlam In Goliath in that it never lets up”.

[78] When asked about their influences in a 2007 interview, Jon Mess said, "We all have such varied music taste that it would be quite a long list," and mentioned At the Drive-In, Cursive, Explosions in the Sky, MF Doom and Radiohead.

[80] Matt Mingus cited Genesis's Phil Collins and Deftones's Abe Cunningham as two of his favorite drummers, while Will Swan called the guitar work of Thursday and At the Drive-In's Omar Rodríguez-López as major influences.