However, municipalities could opt out of the county's minimum wage increase, and many did. According to a Daily Herald analysis of 134 suburbs shortly after the law went into effect, more than three-quarters voted to opt out.
All that might be moot if Illinois lawmakers pass a statewide minimum wage increase. The state legislature in 2017 approved a plan to raise Illinois' minimum wage to $15 an hour over five years. Republican Gov. Bruce Rauner vetoed the legislation. With Pritzker set to become governor and Democrats continuing to control the legislature, some predict it's only a matter of time before Illinois' minimum wage is increased.
Here's what that could mean for the suburbs:
Doing the math
Illinois' first minimum wage was $1.40 an hour in 1972, which has about the same buying power as $8.61 today, according to the Bureau of Labor Statistics. The state's minimum wage approached that amount when Illinois lawmakers increased it to $8.25 in 2010, the current statewide minimum. If that amount increased with inflation, Illinois' minimum wage today would be $9.63 an hour.
Full-time minimum wage workers in Illinois earn about $17,160 a year, assuming they work 40 hours per work and don't take any vacation days. That's about $5,000 above the federal poverty level for an individual, according to the latest guidelines from the U.S. Department of Health and Human Services. But that changes as household size grows. A parent with two children and a minimum wage job would be about $3,600 under the federal poverty guideline.
Illinois vs. others
Eighteen states started 2018 with a higher minimum wage, with some automatically increasing rates based on the cost of living, according to the National Conference of State Legislatures. During the election this month, voters in Arkansas and Missouri approved phased-in increases to $11 an hour and $12 an hour, respectively.
Illinois' other neighbors -- Wisconsin, IowaIndiana and Kentucky -- each follow the federal minimum wage of $7.25 an hour.
California and Massachusetts have laws that will increase the minimum wage to $15 an hour by 2022 and 2023, respectively.
Many suburbs opting out of Cook County's ordinance argued it would hurt businesses in competition with neighbors in DuPage or Lake counties.
Would a statewide minimum wage increase be more appealing? Some suburban leaders still aren't thrilled at the prospect.
"If I have to take this cancer-causing medication, it's better to do it statewide than county by county," said Mike Charewicz, a Des Plaines alderman and owner of an auto repair shop. "If I have to deal with it, at least it being statewide makes it easier to palate."
Like many opponents, Charewicz fears a higher minimum wage could cause a loss in jobs or apprenticeships, which his business offers, as well as wage compression that would drive up all salaries.
Geri Wasserman, a member of Reclaim Northwest Suburbs, which advocates for towns to opt in to the Cook County ordinance, said the group will continue pressuring municipal board members -- even as Pritzker is set to take office in January.
"We feel a statewide minimum wage increase would be great," Wasserman said. "But the question is when will this happen? In the meantime, people are struggling on a minimum wage of $8.25, trying to make ends meet for their families."