Big hits -- some legal, some not so much -- also turned the outspoken five-time Pro Bowler into focal point for a league-wide crackdown on helmet-to-helmet contact.
Harrison's outlaw image made him beloved in Pittsburgh but reviled elsewhere. His onerous contract, however, no longer worked for a team with serious salary cap issues. The Steelers released the former Defensive Player of the Year on Saturday when the two sides could not agree on a more cap-friendly deal.
"It's been a great run but all good things must come to a end," Harrison posted on his Twitter account on Saturday afternoon. "Thank you Steelers Nation I will miss you all!"
Harrison told ESPN's Josina Anderson that he wants to play for a team "that is successful" and that uses a 3-4 defense.
"I want to try and stay in the scheme that I'm in -- in a 3-4 defense," he said. "Warm weather is probably better but sometimes you don't have a choice on where you get to go. You have a choice in picking the team but it still depends on the circumstances around that team. You have to go with what is best for you."
When asked if there was a player he'd like to play with, he said "not really" but mentioned the Patriots' Tom Brady and Broncos' Peyton Manning as players "anybody would want to play with ... who wouldn't."
Harrison said while he's "grateful to the Steelers and the greatest fans in the world," that "chapter is closed and it's time to move on."
"When that time comes, I will jump into it with both feet and go 100 miles per hour. That is just the way I do things," he said.
Pittsburgh general manager Kevin Colbert and Harrison's agent Bill Parise had spent the last few days trying to iron out a new deal but couldn't reach any common ground. Harrison was entering the final two years of a $51-million extension he signed in 2009 and was scheduled to make $6.57 million in 2013.
Harrison was set to make $7.6 million in 2014. By releasing Harrison, the Steelers create $5.105 million in cap space.
They've already put that money to good use, too.
A source told ESPN's John Clayton that the Steelers gave $1,323,000 tender offers to four restricted free agents -- running back Jonathan Dwyer, running back Isaac Redman, wide receiver Emmanuel Sanders and defensive tackle Steve McLendon.
Harrison -- who turns 35 in May -- will find himself looking for work for the first time since he became a fixture on the right side of Pittsburgh's 3-4 defense in 2006.
"James has been an integral part of our success during his years in Pittsburgh and has helped us win two Lombardi trophies during that time," Colbert said in a statement. "We appreciate all of his efforts and wish him the best."
Harrison is the first cap move by the Steelers this offseason as they try to get under the $123 million salary cap by Tuesday, when the new league year begins. Quarterback Ben Roethlisberger and linebacker Lawrence Timmons have restructured their contracts to help get Pittsburgh under the cap number but Colbert told reporters after the Steelers finished a disappointing 8-8 in 2012 "terminations" would also be necessary.
"Sooner or later you have to pay the debt and you never want to get to a point where you have to gut your team and start over because we have to compete for a championship every year," Colbert said in January.
This isn't the first time the Steelers have released a star to save money. They let go wide receiver Hines Ward and linebacker James Farrior last spring, but unlike Ward and Farrior -- who both retired rather than sign elsewhere -- Harrison remains intent on playing in 2013.
Harrison missed the first three games of the 2012 season with a minor knee injury but was one of Pittsburgh's steadiest performers over the second half of the year. He finished with six sacks, tied for the team lead, and a pair of forced fumbles as the Steelers finished No. 1 in total defense for the fourth time since Harrison became a starter.
"James has played a major role in the success of this organization during his time in Pittsburgh," coach Mike Tomlin said in a statement. "I appreciate everything he has done in my six years as head coach."
In many ways Harrison's success is emblematic of "The Steeler Way." Signed as an undrafted rookie free agent in 2002, Harrison spent two years on the practice squad before getting signed by the Baltimore Ravens, who sent the undersized Harrison -- listed at 6-feet -- to NFL Europe for some seasoning. The Ravens eventually cut him loose and Pittsburgh brought him back hoping he had matured.
It ended up being one of the better bargains in team history.
Harrison eventually blossomed into one of the league's most feared pass rushers. He helped the Steelers win their fifth Super Bowl in 2006 and was named the AP NFL Defensive Player of the Year in 2008, when he collected 16 sacks.
Chasing their second championship in four years, Harrison put together one of the most spectacular plays in Super Bowl history, returning a Kurt Warner interception 100 yards for a touchdown on the final play of the first half in a game the Steelers eventually won 27-23.
Yet Harrison's violent play sometimes came at a hefty price. He was fined multiple times for hits to the head.
Feeling he was being unfairly persecuted by the league, Harrison called commissioner Roger Goodell a "crook" and a "devil" during an interview with Men's Journal in early 2011. Harrison later apologized and promised to clean up his act.
It didn't exactly work. Harrison was suspended for a game in December, 2011, after his helmet smacked into Cleveland quarterback Colt McCoy's facemask a moment after McCoy released the ball.
Harrison did not receive any letters from the commissioner's office in 2012 but his physical style of play took a toll on his body. He missed all of training camp with a knee injury and admitted he had endured "a dozen" concussions over the course of his career.
The Steelers hope they have Harrison's replacement in 24-year-old Jason Worilds, who finished with five sacks in limited action last season.
Information from ESPN's Josina Anderson, ESPN NFL Insider Adam Schefter, ESPN Senior NFL Writer John Clayton and The Associated Press was used in this report.