All formed in suburban Los Angeles in 1987 when Milo Aukerman, the lead singer of the Descendents, left to pursue a graduate degree in biochemistry, forcing the band into a hiatus.

The remaining members, guitarist Stephen Egerton, bassist Karl Alvarez, and drummer Bill Stevenson, decided to carry on as a band, adopting the title of the Descendents' last studio album, ALL, as their official moniker.

Following a brief stint in rural Brookfield, Missouri, the band eventually relocated to Fort Collins, Colorado; the centrally located city made touring the west and east coasts of the country considerably easier.

ALL briefly joined major label Interscope Records for 1995's Pummel, but disputes over marketing and promotion of the album ended their relationship quickly.

On January 26, 2008, Egerton, Stevenson, and Alvarez reunited with Scott Reynolds to play a set of All songs as an opening act for Drag the River at the Aggie in Fort Collins.

In July 2009 the band completed a short tour with fellow Cruz Records alums Big Drill Car, going across Southern California.

[1] In an interview with RiotFest.org, Scott Reynolds did not rule out the possibility of writing new material but set three conditions that need to be present: people want to hear new music, he feels the need to create, and the "bro" factor between the bandmates needs to be there.

On September 9, 2014, after a showing of Filmage at the Downtown Independent theater in Los Angeles, ALL played a dual set with both Chad and Scott, followed by a Descendents karaoke part where both Chad and Scott sang Descendents songs, along with surprise guest vocalists: London May (Samhain); Phi Lo (the Last); members of the Filmage crew, James, Justin & Deedle; Jen Razavi (the Bombpops); Marko DeSantis (Bad Astronaut) & Ken Stringfellow (Posies); Dennis Lyxzén (Refused); Davey Havok (AFI); Jim Lindberg (Pennywise); and Matt Skiba (Alkaline Trio, Blink 182).

ALL played two sets at Washington's in Fort Collins, Colorado in November 2019 with Dave Smalley and Scott Reynolds to celebrate the 25th Anniversary of the Blasting Room.

All's mascot is Allroy, a neon bright yellow cartoon character with spiked hair, whorls for eyes, and a large, toothy grin, often depicted engaged in conflict with an anthropomorphic musical note.

Allroy was created by bassist Karl Alvarez, based on a caricature he had drawn of guitarist Stephen Egerton for the Descendents' 1987 "FinALL" tour posters.