Based in Oak Brook, Illinois, and founded in 1893 by businessmen opposed to legislation limiting the working hours of women, IMA has more than 4000 member companies.

[1] On September 29, 1893, Illinois manufacturers met at the Grand Pacific Hotel to organize in opposition to the Sweatshop Law of 1893 that prohibited child labor and mandated an eight-hour workday.

[13] That year, IMA President Greg Baise was required to testify at a Bloomington trial regarding an alleged corporate conspiracy to conceal the hazards of asbestos.

[14] In 2012, the IMA spoke out in favor of Illinois' enterprise zones[15] and was a vocal member of the STOP Coalition, which opposed the construction of a coal power plant with pollution mitigation in Taylorville by Tenaska Energy.

[20] A Komatzu mining truck, built in Peoria and designed to carry 400 tons, won the 2024 “Coolest Thing Made in Illinois” competition.

[21] In February 2025, the association opened entries for its sixth annual “Makers Madness” contest and invited the general Illinois public to vote for “…the coolest product made” in the state.

[26] In 2012, the IMA opposed bills that would require health insurance to cover pre-existing conditions, tie the minimum wage to the consumer price index, and provide coverage for maternity care and sick leave.

[27] IMA President Mark Denzler is an employer representative of Illinois' Workers Compensation Advisory Board[28] and has hosted a weekly poker game in his office frequented by state legislators.

[36][37] In July 2024, IMA signed a letter to members of both the House Committee on Armed Services and the Senate Committee on Armed Services opposing Section 828 of S. 4628, the National Defense Authorization Act for Fiscal Year 2025, entitled "Requirement for Contractors to Provide Reasonable Access to Repair Materials," which would require contractors doing business with the US military to agree "to provide the Department of Defense fair and reasonable access to all the repair materials, including parts, tools, and information, used by the manufacturer or provider or their authorized partners to diagnose, maintain, or repair the good or service.