The band was formed in New Brunswick, New Jersey by Chris Ross (drums), Walt Svekla (bass) and John Fraunberger (guitar) in 1995 and self-produced a demo. In the search for a new vocalist, they found Tim Shaw who was a roadie with Sick Of It All, a band in the New York Hardcore scene.
The band went to California and signed for Indecision Records and in May, 1996 released a self-titled 7" four track EP. After this, Walt Svelka and Chris Ross departed and were replaced by Nate "Edge" Gluck (ex-Strength 691, Vision) and Ryan Murphy (ex-Undertow) respectively. In mid-1997, Fall from Grace, another four track 7" EP, was released. John Fraunberger then left the band to take up a teaching degree, but not before recording material for the first full-length album, Direction of Things to Come which came out in November, 1997. Fraunberger was replaced on guitar by Ryan "Mackenzie" Donoghue as the band took to the road. In 1998, the band decided to cast their net further and sign for Nitro Records which had a larger distribution network. Also in 1998, three live tracks appeared on an Indecision Records 7" Devil's Night, with other artists from the label – the remainder of the live set would later feature on the Three Years Two Months Eleven Days album. 
Although the band had switched labels, they retained the services of the same recording studio (Trax East, South River, New Jersey) and the same producer (Steve Evetts) as their debut on Indecision for the next full-length outing, Cast the First Stone released in March, 1999. While on tour in Ireland, Ryan Murphy decided to leave the band and was replaced by John "Vince Vegas" O'Neill. Before touring Europe in 2000, Ryan Donoghue left the band which, although was on very good terms, left the band with a situation. Nate solved it by employing Chris Oliver for bass duties on the tour (teaching him along the way) while taking up the guitar duties himself.
In April, 2000, Indecision Records released a retrospective album of Ensign material, entitled Three Years Two Months Eleven Days - the precise amount of time the band had spent on the label. It consisted of the first 7" plus three tracks from the same recording session, the Fall from Grace 7" plus two more from the same session, two otherwise unreleased tracks, two tracks from just after the release of Direction of Things to Come sessions and, finally, six tracks recorded live in 1998 at the Showcase Theater in Corona, California – three of which had previously appeared on the Indecision Records 7" Devil's Night.
In June, 2000, the band recorded four tracks in New York for an EP called For What It's Worth which was released in October 2000. They also recorded two tracks which would end up on a Split 7" EP with Death By Stereo released by Indecision Records in December 2000, and a further two tracks which were released on a split 7" with Reaching Forward on European label, Reflections Records. 
In November 2000, the band entered the studio to start recording their third full-length release, The Price of Progression. Chris Byrnes came in December to add some second guitar parts as Nate was performing on bass and guitar, as well as the usual backing vocals. Chris Oliver had played bass on the initial takes as a favor to Nate, and continued to play for a while after. The band were also joined on vocals for guest spots by Russ Rankin of Good Riddance and Andy West of Kill Your Idols. The record was finally released in April, 2001. Also, in February 2001, Indecision Records re-released their split 7" with Death By Stereo on CD as part of their Split Series compilation.
In 2002, they headed out on a Canadian tour supporting metalcore band, Hatebreed. A tour of Europe with Avail followed in 2003.
The band found a regular guitarist in Frank Piegaro in 2002, while John O'Neill had been replaced by Brian "Pnut" Kozuch in 2001. They took to a studio in Hoboken, New Jersey and in seven days recorded twenty cover versions of artists such as Bad Brains, Descendents, Dag Nasty, Hüsker Dü, Misfits and Discharge, all seminal punk bands who had influenced members of Ensign in their formative years. The record was released in October, 2003, on Blackout Records – they had agreed to do this for label owner, Bill "Blackout" Wilson, with Tim Shaw having worked with and for him during the early Indecision Records days – and it was called Love the Music, Hate the Kids. In Europe, it was released by German label, JoinTheTeamPlayer.
In November 2003, UK-based record label, Household Name released a split EP with Ensign and Leeds, UK based hardcore band Fig 4.0. It featured three tracks from Ensign: "A Place", "Circa 1985" and "Three Can Keep A Secret" and was limited to 500 releases on 7" vinyl.Tim Shaw – vocals
Dan Brennan – guitar
Nate Gluck – bass, guitar (2000 – 2002)
Corey Perez – guitar
Derek Reilly – drums
Walt Svekla – bass (1995 – 1996)
Ryan Murphy – drums (1996 – 1999)
Chris Ross – drums (1995 – 1996)
John Fraunberger – guitar (1995 – 1997)
Ryan "Mackenzie" Donoghue – guitar (1997 – 2000)
John "Vince Vegas" O'Neill – drums (1999 – 2001)
Chris Oliver – bass (2000 – 2002, live performances and rehearsals)
Chris Byrnes – guitar (2001 – 2002)
Frank Piegaro – guitar (2008 – 2011)
Brian "Pnut" Kozuch – drums (2008 – 2011)
The following people are credited as playing with the band temporarily Graham Gardner – vocals in 1995
Vin Villanueva – guitar in 1995
Steve Cunningham – guitar in 1997
Mike Hartsfield – guitar in 1998
Dan Palmer – guitar in 1998
Brian Melville – guitar in 1998
Dan Sobon – guitar between 2002 – 2003
Steve Larger – drums in 1999
Benny Horowitz – drums in 2001
Mikey Erg – drums in 2011
Kevin White – guitar in 2011
Brian Maguire – drums in 2011 – 2012
Self-titled 7" EP (May 1996) Indecision Records
Fall from Grace 7" EP (June 1997) Indecision Records
Ensign / Good Riddance Split 7" EP (1997) Orphaned Records
Direction of Things to Come (November 1997) Indecision Records
Devil's Night Compilation 7" (1998) Blackout Records
Cast the First Stone (March 1999) Nitro Records
Three Years Two Months Eleven Days (April 2000) Indecision Records
For What It's Worth (EP) (October 2000) Nitro Records
Death By Stereo/Ensign Split 7" (EP) (December 2000) Indecision Records
Ensign/Reaching Forward split 7" (2000) Reflections Records
The Price of Progression (April 2001) Nitro Records
Love the Music, Hate the Kids (October 2003) Blackout Records
Ensign/Fig 4.0 Split 7" EP (November 2003) Household Name, UK
Scream For Help! compilation 2x10" (May 2006) KOI Records