Only days after Democrats made Hillary Clinton the first woman to win a major party's presidential nomination, Massachusetts Gov. Charlie Baker signed another milestone in gender equality.

The bill signed Monday prohibits employers from paying women less for “comparable work” within the same company. Exceptions are provided for other factors that might contribute to variations in pay, such as seniority, a “bona fide” merit system, sales or other bonus-based quotas, location, amount of travel and training or other levels of education. It takes effect July 1, 2018.  

The law was approved unanimously by the House and Senate, and was supprted by the Chamber of Commerce and advocates for equal pay, like the National Organization for Women. 

Activists said the signing represents a culmination of 20 years of work by advocates looking to close the gender pay gap in the state. 

"This bill finally recognizes that pay inequity is a problem," state Sen. Patricia Jehlen, who herself filed many similar bills throughout her legislative career, told WBUR. "It doesn't solve the problem, but it removes many barriers which we know have kept women from achieving equity."

In Massachusetts, women make an average of 82 percent of what their male counterparts do for comparable work. That's slightly higher than the national rate of 79 percent. 

For women of color in the Bay State, the contrast is even starker: African American women make 67 percent, while Latinas make only 59 percent. 

“The impact of those differences in wage is extraordinary,” Victoria Budson, the executive director of Harvard’s Women in Public Policy Program said. “In the city of Boston, nearly half of the children are in households that are headed by women … [so] it’s not just for that woman, but it’s for her family, it’s for her community.” 

Employees who believe they are victims of pay discrimination can sue their employer for lost wages, and, if successful, are entitled to an additional punitive award in an amount equal to those lost wages. Charges of employer discrimination can also be filed directly with the state attorney general’s office, who may elect to take up the case on the party’s behalf. 

In a first-in-the-nation move, the law also bars employers from asking applicants about their wage history during the interview and salary negotiation process. Hiring managers will be able to ask past employers for such information only after a formal offer has been extended to the candidate. 

That provision will help all kinds of workers — not just women —  secure the pay levels they deserve, Budson said. 

“That kind of discrimination is like a snowball rolling downhill,” said Budson, who also chairs the state’s Commission on the Status of Women. “If an employee in their first job were paid less than their male counterpart in that job, and each subsequent employer asks what they made at that last job, their salary would continue to be benchmarked against that wage, which wasn’t a fair market wage, which wasn’t an equitable wage. 

“What happens over time is that snowball continues to roll downhill, and the level of underpayment gets larger and larger over time — not smaller,” she continued. “It’s cumulative and can have an enormous impact.” 

The new rules also enable employees to discuss their salaries, wages and compensation with anyone that they choose, without retaliation from management. 

There are also protections for employers: companies that make a good faith effort to audit their own wage practices and correct inequities discovered on the payroll will be shielded from discrimination lawsuits based on these new provisions for three years. 

“The most important thing is not only did something get passed, but this bill really provides enormous gains for the Massachusetts economy, for women, for businesses and for men,” Budson said.