A bill on Gov. Charlie Baker’s desk would make Massachusetts the only state in the union where employers can no longer ask job applicants how much they were paid in previous jobs.

Though that’s been a routine workplace query, it has perpetuated a pattern in which women have earned less than men for comparable work.

The landmark pay equity legislation landed on the governor’s desk just days before the Democratic Party made history by nominating a woman, Hillary Clinton, to be its candidate for the presidency.

A sense of history, and gender justice, attends both of these developments.

More than 70 years ago, Massachusetts became the first state to pass a law prohibiting pay differentials based on gender. In notching another national “first,” the new pay equity bill, which Baker is expected to sign, seeks to actually bring about a world in which an employee’s talents and training, not gender, determine the rate of pay.

Despite the 1945 state law, a gender pay gap has persisted here in the Bay State. Women in this state are paid 82 cents for every dollar earned by their male counterparts, according to the National Partnership for Women & Families.

That statistic captures the reality of unequal pay for equal work. And after decades of failed efforts to address this in the state Legislature, last weekend’s unanimous backing in the Senate represents a monumental breakthrough.

Candidate Clinton has spoken often of glass ceilings. In a remote linkup Tuesday to the Democratic National Convention audience in Philadelphia, a television graphic showed glass shattering – and the candidate coming into view.

For businesses in Massachusetts, getting this far on a pay equity bill had to overcome fears of other things breaking. Before it fell in line as a supporter, the business group Associated Industries of Massachusetts wanted assurances that employees would not be hit by an avalanche of pay discrimination lawsuits. The bill that emerged from both the House and Senate has addressed that concern by saying that employers will be protected from legal liability if they conduct self-evaluations of their pay policies and if they show reasonable progress in addressing disparities that appear to be based on gender.  

Though a practical and fair bill eventually won over AIM, other business groups, including the Massachusetts High Technology Council, continue to oppose the measure. The council didn’t like early versions of the bill, the Boston Globe reported last week, but didn’t like the compromises made either.

A spokesman for Senate President Stanley C. Rosenberg said the bill sought to be practical, effective and sustainable. It is practical in the sense that it recognizes that there are instances in which a man, or a woman, might earn more than someone in a similar position. But that pay difference must be based on a group of factors — a worker’s seniority, his or her education, training and experience, or the use of a compensation system that measures the quantity of goods or services produced, as in sales positions, for example.   

On its journey to the governor’s desk, this measure was poked and prodded, gaining strength as it went along. Changes didn’t only make the bill more palatable to employers. The measure stipulates that employers cannot reduce a salary to bring a pay level into line for employees of different genders. If signed by Baker, the law would go into effect July 1, 2018. That gives employers ample time to study their pay policies and, if necessary, show progress in eliminating pay differences that have been a holdover from an earlier age, when men’s wages were viewed as most important to households and women’s earnings, in some cases, were demeaned as “pin money.”

As dated as that term sounds, in a country where women today are the sole or primary breadwinners in four out of 10 households with children under the age of 18, the relic of pay discrimination has persisted. It has taken decades for the Legislature to fashion a measure designed to root it out. It is now up to Baker to enable Massachusetts to again lead the nation on a vital issue of fairness.