Andrew McMahon began his musical career as the lead vocalist and pianist for the Orange County piano rock band Something Corporate.

The primary impulse behind McMahon's solo project, Jack's Mannequin, was a song he recorded in December 2003 titled "Locked Doors".

While Something Corporate's other songwriter and lead guitarist Josh Partington created a side project of his own called Firescape, McMahon started writing his own songs.

However, after growing "bored of 'the' band names," he decided to sandwich it together with the title of a song he had completed for the record, "Dear Jack".

[7] A summer tour was scheduled to support the record release, but was canceled after McMahon was diagnosed with acute lymphoblastic leukemia and received a stem cell transplant from his sister Kate.

[8] Music by Jack's Mannequin from Everything in Transit was featured in Season Three, Episode Fifteen of the TV series One Tree Hill.

[9] Hilarie Burton's character on the show, Peyton Sawyer, appeared in the music video for 'The Mixed Tape,' from Everything In Transit.

Also, in February 2008, videos of live performances of two songs off the record ("Caves"[13] and "Suicide Blonde"[14]) were uploaded onto YouTube for public viewing.

[15] The album was entitled The Glass Passenger, and is a transcendent step-up, a catchy and listenable journey through McMahon's stories of love, life, and loss that moves from full-on upbeat rock ("Spinning") to melancholy introspection ("Annie Use Your Telescope") and all that lies between.

Another EP, In Valleys, was released on iTunes on September 9, containing one song from the album, "Swim," and three b-sides, "Cell Phone", "Sleazy Wednesday", and "At Full Speed".

On August 28, 2008, in an interview with MTV, Andrew revealed that the author Stephenie Meyer had written the treatment for the music video for "The Resolution" and was set to direct it the following week.

In the time following the last Jack's album the people in my world were moving in together, getting married, trying to find quote unquote 'real jobs' and reconciling new lives that looked a lot less like youth than some of us cared for.

Marriage is a bit of a beast to tackle in a pop record but when I wrote 'My Racing Thoughts,' it became clear how powerful and loaded a subject this kind of love is and somewhere in that moment I began to lock into the broad concept for the writing sessions to come."

[27] Special guests for the shows included Jonathan "Dr. J" Sullivan, Jacques Brautbar, Matt Thiessen, and Stacy Clark.