|Origin||Green Hill, Alabama|
|Years active||2001 – present|
|Labels||New West Records, Lightning Rod Records|
|Associated acts||Drive-By Truckers
Jason Isbell and the 400 Unit
Jason Isbell (born February 1, 1979) is an American singer, songwriter, and guitarist from Green Hill, Alabama, in Lauderdale County. He is best known as a former member of Drive-By Truckers and for his solo career.
In 2013, Isbell released his fourth solo album, Southeastern, to widespread critical acclaim.
Almost all of Isbell's family, except his parents, were musicians, and his father was an avid music listener. After some work as a songwriter, in 2001, Isbell joined the rock band Drive-By Truckers while they toured in support of their album Southern Rock Opera. Isbell recorded and wrote with the Truckers for their next three albums, and for most of this time was married to Shonna Tucker, who joined the band as a bassist after Isbell. The two later divorced.
On April 5, 2007, Isbell announced that he was no longer a member of Drive-By Truckers. The following day, Patterson Hood confirmed the break on the band's official site. In his letter to the fans, Hood described the parting of ways as "amicable" and expressed the hope that fans would continue to support Drive-By Truckers as well as Jason's solo efforts.
Jason Isbell released his first solo album, Sirens of the Ditch, on July 10, 2007.
Jason Isbell and The 400 Unit's eponymous album was released on February 17, 2009, on Lightning Rod Records. Jason Isbell and The 400 Unit is Isbell's second solo release and his first release with his band The 400 Unit. Matt Pence of Centro-Matic serves as co-producer, drummer and engineer.
Isbell and the 400 Unit released their second album, Here We Rest, on April 12, 2011, on Lightning Rod Records. The album was produced and recorded by the band themselves.
In 2012, Isbell supported singer-songwriter Ryan Adams on his tour. Both played solo, acoustic sets.
On June 11, 2013, Isbell released his fourth solo album, Southeastern. Produced by Dave Cobb and featuring accompanying vocals by Kim Richey and Shires, Southeastern received positive critical reviews, earning a score of 88 on Metacritic.
Emergence of the 400 Unit
The "400 Unit" was the former colloquial name of the psychiatric ward of Florence, Alabama's Eliza Coffee Memorial Hospital, which is now named the Behavioral Health Center, or One North, and is located on the hospital's first floor. 
Isbell's current band, Jason Isbell and the 400 Unit, is primarily made up of other Alabama musicians. The lineup is currently:
- Derry DeBorja (keyboards) formerly of Son Volt.
- Jimbo Hart (bass)
- Chad Gamble (drums) brother of Al Gamble.
- Sadler Vaden (guitar) also of Drivin' N Cryin'.
- Studio Albums
- Sirens of the Ditch (2007)
- Jason Isbell and The 400 Unit (2009)
- Here We Rest (2011)
- Southeastern (2013)
- Live Albums
- Live at Twist & Shout 11.16.07 (2008)
- Live from Alabama (2012)
- Duesenberg Starplayer TV Goldtop
- Fender Stratocaster
- First Act Custom Delgada w/ Bigsby
- First Act Custom Delia LS w/ Bigsby
- First Act Delia LS (standard fixed-bridge version)
- Gibson Les Paul Standard
- Gibson ES-335
- Reverend Buckshot
- Reverend Flatroc w/ Les Trem
- Harmony Archtop 
- Sommatone Roaring-40 head & 2x12 Cabinet
- Marion Henry Guitar Pedals
- Mr. B's Bottleneck Guitar Slides
- POG electro-harmonix octave generator;
- ZVex Box of Rock overdrive, Analog.man 
- Deeds, Michael."Southern singer-songwriter Jason Isbell keeps on Truckin.'" January 25, 2008. IdahoStatesman.com. Retrieved 2008-01-26.
- Dodds, M.S. "Jason Isbell: Not Far From The Tree." Illinois Entertainer. June 27, 2007.
- Schmergel, Daniel Patrick. "An Artist Revealed: Interview with Jason Isbell." lostwriters.net.
- Mitter, Siddhartha. "He'll keep on trucking, but solo." Boston Globe July 15, 2007.
- Hunt-Murphy, Ronan. "Album News: Jason Isbell & the 400 Unit – Here We Rest" Swear I'm Not Paul
- Kerns, William. "Happily engaged Shires makes return appearance in hometown". Lubbock Avalanche-Journal. Retrieved January 1, 2014.
- Wilson, David. "Post Trucker – A Review of Here We Rest" Frontier Psychiatrist
- An Interview With Jason Isbell – Here We Rest; hearya.com, april 2011