Having previously signed netminder Cristobal Huet to a four-year deal worth an average of $5.625 million a year, Tallon has significantly upgraded a Blackhawks team that fell just three points shy of the postseason last spring.
Playing for Buffalo and then San Jose down the stretch last season, Campbell tied for third among all NHL defensemen with 62 points. He was plus-8.
"We decided we'd try to make an impact today to give our fans something to get excited about," Tallon said. "When you do that, you're going to overpay, but now we have the resources and the ability to do that."
If there was another area the Hawks needed to improve in order to be considered a serious playoff threat in 2008-09, it was in goal.
Huet was a key factor in the resurgence of the Washington Capitals, going 11-2 after being acquired from the Montreal Canadiens at the trade deadline. He helped Washington win the Southeast Division crown and earn a trip to the postseason.
"Our No. 1 priority was to solidify goal and defense and then move forward," Tallon said.
Campbell is expected to help boost a power play that ranked 24th in the league last season. He scored five power-play goals last season.
"He can move the puck, skate up ice and get you out of trouble," Tallon said. "The power play, at the point, is what he does best."
Huet's addition will increase speculation the Blackhawks will move veteran netminder Nikolai Khabibulin, although his $6.75 million price tag for the 2008-09 season may hold many teams back.
Although Khabibulin (23-20-6, .909 save percentage) was at times steady last season, he allowed far too many weak goals and the young, talented Hawks finished tied for ninth with Edmonton and Vancouver, three points out of the last Western Conference playoff berth.
The Blackhawks also announced they had acquired a future second-round draft pick from the Calgary Flames for the rights to restricted free agent forward Rene Bourque. Bourque played in 62 games with Chicago last season, scoring 24 points -- including 10 goals.
Senior writer Scott Burnside covers the NHL for ESPN.com. Information from The Associated Press was used in this report.