SPRINGFIELD, Ill. (AP) — A turf war over a football team is developing between two Midwestern states with a sometimes-discordant history.

The storied Chicago Bears want to leave historic Soldier Field, where they've played for half a century. Indiana lawmakers are attempting to lure them from the Windy City with a plan to finance and build a domed stadium in Hammond, Indiana, about 25 miles (40 kilometers) from their current home on Lake Michigan's shore.

The Illinois General Assembly has responded with legislation that would give tax breaks to so-called megaprojects of at least $100 million, a plan that would encompass the Bears' proposal to build a complex in the northwest Chicago suburb of Arlington Heights, about the same distance from Soldier Field as Hammond.

Critics complain it's a bad deal for Illinois, where property taxes are already among the highest in the nation — especially when taxpayers still owe hundreds of millions of dollars on a Soldier Field renovation from two decades ago.

Here's a look at what's shaping up to be a showdown.

Why the big deal?

The Bears, one of only two remaining NFL founding members, are legend. Their nine championships, including a Super Bowl win, are second only to the rival Green Bay Packers — though recent decades have brought mostly heartbreak. The franchise carries an $8.9 billion price tag, among the most valuable of the NFL’s 32 teams, according to Forbes.

Born in the central Illinois city of Decatur in 1920, the Bears have called Chicago home for 105 years. Losing them to the Hoosier State would be a major thumb in the eye.

What's wrong with Soldier Field?

With 61,500 seats, it's the NFL's smallest. The Bears have always rented their facilities — the Cubs' Wrigley Field from 1921 to 1970, and Soldier Field, maintained by the Chicago Park District, since. Like most teams, they want to own a stadium, giving them control over operations, scheduling and revenue streams from ticket sales, concessions, parking, naming rights and more.

And Soldier Field is open air. An enclosed facility would allow for other marquee sporting events: Super Bowls, NCAA Final Fours or WrestleMania, for instance.

Why the imbroglio between the states?

Along with the states' established cultural and economic differences and an intense college basketball rivalry, the political fissure between Democrat-dominated Chicago and conservative Indiana has widened. It amped up last year when Indiana adopted a commission to study changing the state's boundaries to include some central Illinois counties whose voters have approved ballot measures calling for secession from Chicagoland.

Arlington Heights, back to Chicago, to Hammond

The Bears have threatened to leave Chicago previously. When they broached moving in 1975, then-Mayor Richard J. Daley replied, “Like hell they will.”

But the City of Big Shoulders heaved an anxious sigh in 2023 when the Bears paid about $200 million for a 326-acre (132-hectare) former horse-racing track in Arlington Heights. They have envisioned a $5 billion, taxpayer-assisted development for a domed stadium and campus of housing, hotels, entertainment and retail space.

In 2024, the Bears offered a $5 billion plan, partially taxpayer-funded, for an enclosed stadium next to Soldier Field, which garnered little interest in the capital of Springfield. Late last fall, the team turned to Indiana.

Where the proposals stand

Indiana's lure creates the Northwest Indiana Stadium Authority to finance, construct and lease a domed stadium near Wolf Lake in Hammond. Indiana Gov. Mike Braun signed it into law on Feb. 26. The Bears would agree to a 35-year lease. Borrowed state money would cover the as-yet-unknown cost of construction, repaid by increased local hospitality taxes.

In Illinois, majority Democrats have advanced legislation in the House that would provide incentives for any so-called megaproject of at least $500 million — or less, down to $100 million, depending on the number of jobs created. Developers would pay property taxes frozen at the parcel's pre-construction value for as long as 45 years. During that time, they would make annual payments in lieu of taxes negotiated with local governments. There would also be a sales tax exemption on building materials for up to 15 years.

Critics claim weakness in Illinois plan

Opponents say the Illinois legislation, with its decades-long property tax freeze, would simply mean increased taxes for homeowners and other businesses — the payment in lieu of taxes would be a bonus.

Democratic Gov. JB Pritzker, who supports the plan, last week countered that the proposal would encourage development on land that isn’t producing property taxes while ensuring increased revenue for local governments.

Meanwhile, a substantial debt remains on the last accommodation. Taxpayers in 2001 put up $399 million to finance a $587 million renovation of Soldier Field. With interest, the remaining tab is $467 million, according to the state's Commission on Government Forecasting and Accountability.

The Bears' $7 million annual lease runs through 2033. Breaking it would cost the Bears a $10.5 million penalty for each year left on the agreement.