[1][2] Jackson then enrolled at the University of Arkansas and played three games for the Razorbacks as a freshman but suffered a season-ending injury.

[5][6] In 2003, after trailing on the depth chart to future first round draft pick Matt Jones, Jackson transferred to Alabama State University and led the Hornets to an 8–5 record, Southwestern Athletic Conference (SWAC) Eastern Division title, and berth in the SWAC Championship Game.

[7] As a junior in 2004, Jackson won SWAC Championship MVP in Alabama State's second 10-win season in school history.

[8] Vikings scouts and personnel had reportedly been watching him closely in secret over his senior season, particularly liking his performance in the East-West Shrine Game.

[13] Vikings coach Brad Childress was quoted days before the draft as saying he was interested in finding a "developmental guy", a "diamond in the rough" quarterback of the future, raw talent he could teach a system.

His pre-season performance was enough to surpass second and third-string quarterbacks Mike McMahon and J. T. O'Sullivan on the depth chart.

After the pre-season, McMahon and O'Sullivan were cut from the team and Brooks Bollinger was brought in, whom Jackson then competed against for the number two spot.

Packers quarterback Brett Favre only managed a slightly better 52% completion rate (26–50) and threw two interceptions.

[22] Jackson had nine touchdowns and 12 interceptions, along with a 159 yards per game, causing the Vikings to have the second-worst passing offense in the NFL.

Jackson missed three games because of injuries, which included a strained groin, a concussion and a fractured index finger.

Analysts put the Vikings' 8–8 record on the successful running of Chester Taylor and rookie Adrian Peterson, which took the pressure off of Jackson and the defense.

The Vikings returned seven players that were in the 2008 Pro Bowl (only three teams had more), and spent $60 million in guaranteed contract money upgrading their team with Jared Allen, traded from the Kansas City Chiefs, and free agents Bernard Berrian and Madieu Williams.

Several analysts believed better quarterback play was all that was needed to make the Vikings one of the top contending teams in the NFL, and with the Green Bay Packers losing Brett Favre the NFC North Division was up for grabs.

[30] Head coach Brad Childress decided to stay with Jackson as the starting quarterback and brought in Gus Frerotte to be his backup.

It was widely reported in the off-season that Jackson had a new swagger, handled situations in practice well where he looked lost in the previous years, and had an improved grasp of the Vikings offensive system.

[31] Childress threw a "Coaching 101" clinic for media reporters in which he played a tape of Jackson showing the progress he made in 2007 through a series of missed passes or poor decisions that he made in early games but executed properly in later contests and concluded with some tape of him hitting a target net with every 15-yard pass he threw during an offseason drill.

[citation needed] After being relegated to backup after the loss to the Colts, Jackson saw his next significant action in Week 14 against Detroit, where he played the entire second half in place of an injured Gus Frerotte.

[37] The following week, with Frerotte still injured, Jackson was the starting quarterback against the Arizona Cardinals and he played arguably the best game of his career.

[42] The Vikings season ended in the Wild Card Round of the playoffs with a loss to the Philadelphia Eagles.

[43] Jackson went into the 2009 season in competition for a starting job with Sage Rosenfels, who the Vikings had acquired from the Houston Texans.

[44] The Vikings also pursued former New York Jets and Green Bay Packers quarterback Brett Favre, who had retired after the end of the 2008 season.

[citation needed] That changed, however, when Favre announced that he would play for the Vikings after all, signing with the team on August 19.

[46] Jackson, Rosenfels, and 2008 third-stringer John David Booty were believed to be competing for two roster spots, and for the primary backup job.

[47] Jackson helped his case with a strong performance in Favre's debut game against the Kansas City Chiefs, throwing for 202 yards and two touchdowns in backup work.

[56] Jackson officially signed a two-year contract with the Seattle Seahawks on July 29, 2011[57] and was announced as the starting quarterback shortly after.

[58] In Seattle, he had been reunited with offensive coordinator Darrell Bevell and wide receiver Sidney Rice both members of the Vikings during his time there.

Along with wide receiver Mike Williams, Jackson was appointed to offensive team captain, which was previously owned by Matt Hasselbeck, who signed with the Tennessee Titans.

[67] Jackson competed with Brady Quinn for the backup quarterback spot behind starter Russell Wilson.

[73] Seahawks coach Pete Carroll said that the team was interested in re-signing Jackson, though they ultimately opted to roster undrafted rookie Trevone Boykin as their backup quarterback the following season.

[77] Jackson was arrested on June 25, 2016, in Kissimmee, Florida, and charged with aggravated assault after police said he threatened his wife with a gun.