CHICAGO — Dedra Farmer was so good at her job as a Wal-Mart department manager in Oklahoma that her bosses assigned her to train new Tire and Lube Express Division managers, all of whom were men.

After she got done training them, the men went to work for $2,000 more a year than she got paid.

It’s much the same story in the Windy City.

Alice Banes, 29, a sales worker at Macy’s State Street store, told the World, “You have to be better than the men at work. You have to take care of family and still do better here at work just to prove you can hack the job and be a mother at the same time. It gives me a lot of stress.”

Brenda Carr was alone at the checkout counter with eight customers in line at Walgreens on the city’s South Side. A male department supervisor passed by, demanding to know why she hadn’t already “fronted” the shelves. She answered discreetly by glancing first at him and then at the long line approaching her register.

“Then do it in between the customers,” he snapped.

Carr told the World that he wasn’t even her boss. “He’s a department supervisor like me. I’ve been here a year longer than him and I know he gets $2 more an hour than me.”

A waitress at a coffee shop near the North Side campus of Loyola University, who asked that her name be withheld, pointed to a much younger male waiter and complained, “Not only do I get paid 50 cents less than him, but I’m worried because I’m 50 years old now.

“We’re supposed to act young and be sexy and wear this uniform,” she said, pulling on the collar of her sleeveless blouse. “It’s a lot skimpier than what I’d like to wear, plus even the nastiest, most obnoxious guy who comes in here has to be treated as if he deserves to have a damned red carpet rolled out for him.”

She was asked if she considered sexual harassment an occupational hazard. Nodding agreement, she began talking about her boss: “He looks at us as if we are no better than the utensils in here. He’ll walk into the room where we change into our uniforms and pat you on the shoulder. When I asked him to quit he said, ‘Be a good girl.’”

Women’s groups descended on Congress two weeks ago to address some of these problems, particularly the wage differential between men and women.

Using median pay figures, the groups say it takes a year and four months for a woman to earn as much as a man does in a year. Looked at in another way, a woman typically earns 80 cents for every dollar earned by her male counterpart.

That wage differential, a source of enormous extra profits for businesses, puts a downward pressure on men’s wages, too.

Unionists, led by the Coalition of Labor Union Women, the American Federation of Teachers and other pay equity groups rallied outside the Capitol and lobbied members of Congress inside.

They pushed for passage of a bill introduced by Rep. Eleanor Holmes Norton (D-D.C.) and Sen. Tom Harkin (D-Iowa) titled the Fair Pay Act. The measure would put teeth into the 44-year-old federal equal pay law by increasing penalties for pay discrimination based on sex and by making it much easier to prove pay discrimination based on sex.

Dedra Farmer, the Wal-Mart supervisor who was paid less than the men she had trained, was among those who testified in Congress for the bill. Farmer has also joined 1.6 million other women, all of them current or former Wal-Mart workers, who have filed a class action suit against the firm for sexual discrimination in pay and promotions.

The negative impact of unequal pay on families is evident, particularly where lower pay forces women to work longer hours.

Charlotte Michaels, 36, a cashier at a Dominick’s supermarket who recently gave birth to a baby girl, said, “We need some paid time off to take care of our children. Having a baby deserves more than six weeks to recover.”

Carr, the Walgreens worker, said, “There are a lot of women out here who work hard. I work so much and such long hours that my kids ask me on the phone” — she waved her cell phone — “‘Mom, please come home, when are you coming home? We want to see you, mommy. Please come home.’”