Kenneth Pattengale and Joey Ryan formed the group in early 2011, shelving their solo careers in favor of a collaborative project that focused on harmonized vocals, entwined acoustic guitars, and rootsy songwriting. From the very beginning, the Milk Carton Kids worked fast, releasing a live album (Retrospect) in March 2011 and returning three months later with their full-length studio debut, Prologue. Both recordings were released for free via the band's website. The guys toured heavily, too, pulling double duty as Joe Purdy's opening act and backing band during a spring 2011 tour before launching a headlining tour of their own after Prologue's release.

Despite earning comparisons to Simon & Garfunkel, the Civil Wars, and the Everly Brothers, the Milk Carton Kids' minimalist, down-home material had more in common with Gillian Welch and David Rawlings' duets. As a result, Pattengale and Ryan smartly marketed themselves to the Americana crowd. After closing out 2011 with a performance on NPR's roots rock concert program Mountain Stage, the two spent most of 2012 on the road with other folksy acts, including Old Crow Medicine Show and the Lumineers. The Ash & Clay, the duo's sophomore studio outing, arrived in 2013 via the ANTI- record label. The album was supported by a performance on late-night TV's Conan of their uptempo "Honey, Honey," which highlighted Pattengale's impressive speed-fingerpicking skills, as well as an appearance on the legendary American live-music television series Austin City Limits. The band was also featured in the 2013 documentary Another Day, Another Time: Celebrating the Music of Inside Llewyn Davis, inspired by the Coen Brothers film.

In 2014, a concert DVD titled Live from Lincoln Theatre (recorded in September 2013) was issued by ANTI-/Epitaph, The Ash & Clay was nominated for a Best Folk Album Grammy, and they won Group of the Year at the Americana Music Awards. After continued extensive touring and writing on the road, the duo decided to record songs for their third LP in live performance at pre-show empty venues across North America. In the end, about half of the record was recorded at Downtown Presbyterian Church in Nashville, with all tracks capturing various venues' natural reverb. The resulting Monterey was released in May of 2015. ~ Andrew Leahey & Marcy Donelson