The Slammers compete in the Frontier League (FL) as a member of the West Division in the Midwest Conference.

The Slammers captured their first Frontier League championship in their inaugural season, beating the River City Rascals 3 games to 1.

[1] The team name refers to the famous prisons of Joliet and Will County (Joliet Correctional Center and Stateville Correctional Center) as well as a common baseball term.

The Slammers are one of the three Frontier League teams located in the Chicago metropolitan area, along with the Windy City ThunderBolts and Schaumburg Boomers.

They replaced the Joliet JackHammers of the Northern League after the franchise was crippled by numerous financial issues.

The JackHammers franchise was put up for sale and Steel City Baseball, LLC, bought out all assets, including the front office, the ticketing system, and the lease of the ballpark.

On September 18, 2011, the Slammers were named Frontier League champions after defeating the River City Rascals, 6–5 in Joliet, taking the best-of-five Frontier League championship series three games to one.

Following the 2012 season, the Slammers were purchased on October 15, 2012, by Joliet Community Baseball & Entertainment, LLC.

Kaleb Ort became the first Joliet Slammers player to make it to the MLB.

He made his major league debut on September 13, 2021 as a member of the Boston Red Sox in a game against the Seattle Mariners.

Dietrich Enns had previously played for the Minnesota Twins in the 2017 season.

He has moved around the Twins', Padres', and Rays' minor league teams before coming to Joliet due to the COVID-19 pandemic.

Enns was picked up by the Tampa Bay Rays after pitching just 18 innings for the Joliet Tully Monsters in the City of Champions Cup, a four-team league hosted by the Joliet Slammers.