Vice President Biden speaks at a Wednesday reception honoring Sen. Barbara A. Mikulski (D-Md.) on Capitol Hill. (Melina Mara/THE WASHINGTON POST)

Since arriving on Capitol Hill in January 1977, the onetime social worker and outspoken liberal Democrat from blue-collar Baltimore has championed the rights of women, children, seniors, veterans, federal workers and the disadvantaged.

And over her career, her office became a springboard for women who hold influential jobs in and out of government.

Mikulski’s milestone was saluted Wednesday with a standing ovation and long series of speeches on the Senate floor in an increasingly rare bipartisan tribute. (The previous record-holder was congresswoman Edith Nourse Rogers (R-Mass.), who died in 1960 after 35 years of service.)

Mikulski — known as “Senator Barb” to some colleagues and aides, and a holy terror to others — was the first female senator elected in her own right. As Sen. Dick Durbin (D-Ill.) noted, she did not get there “because of a husband or a father or someone else who served before her in higher office.”

Minority Leader Mitch McConnell (R-Ky.) praised her as “both tough and resilient,” while Sen. John Kerry (D-Mass.) recalled her fury over learning that women had been excluded from a medical study because of hormonal differences from men. “My hormones rage because of comments like that,” Kerry remembered Mikulski saying at the time. 

At just 4-foot-11, the senator, who often stands on a box to peer over a lectern, turned her signature humor on herself in the august chamber.

“You know, for me, history books were Jane Addams and Abigail Adams and powdered wigs,” she said. “I just welcome a day when I even have time to powder my nose, let alone powder my wig.” 

Mikulski credits her Polish American family and the nuns who educated her for instilling a sense of public service. Her father, Willy Mikulski, ran a grocery store in Baltimore’s working- class Highlandtown neighborhood, and young Barbara delivered food to homebound elderly.

As a student at the Institute of Notre Dame, where House Minority Leader Nancy Pelosi (D-Calif.) also attended high school, and at Mount St. Agnes College, Mikulski said that she learned it was better to light the proverbial “one little candle” than to “curse the darkness.”

She told Senate colleagues that she considered becoming a nun, “but that vow of obedience kind of slowed me down a bit.” Cue the knowing laughter.

Instead, she got a master’s in social work from the University of Maryland, became a community activist, won a seat on the Baltimore City Council, lost a Senate race to moderate Republican incumbent Charles Mathias and, finally, in 1976, won her first U.S. House race.  

When she moved to the Senate in 1987, the only other woman in what’s been called the world’s most exclusive club was Kansas Republican Nancy Kassebaum.

 Mikulski was less than thrilled that 1992 was dubbed “the Year of the Woman,” owing to a large number of female candidates, winners and losers. The label, she said at the time, “makes it sound like the Year of the Caribou or the Year of the Asparagus. We’re not a fad, a fancy or a year.”

Today, Mikulski has 16 female colleagues, and they try to meet for dinner monthly in a “a zone of civility.” 

Sen. Olympia Snowe (R-Maine), who cited toxic partisanship as her reason for not running for reelection this year, told CNN that she attends the dinners because “we naturally bond, and we have an opportunity to let our hair down.” Perhaps more importantly, “we are all a team as women. We may not agree on every issue, but that’s not the point. We know how to work together in the give and take and achieve results.”

Mikulski’s office has also been an incubator for women who have gone on to major careers. Wendy Sherman, who as undersecretary of state for political affairs is the State Department’s No. 3 official, cites several fellow former staff members who hold powerful posts, including Diane Thompson, chief of staff for the Environmental Protection Agency; Lisa Jackson, EPA administrator; Ann Lewis, a longtime Democratic operative; and Carol Tucker Foreman, consumer and food-safety issues advocate.

As for Mikulski being a difficult boss, Sherman said via e-mail that most of the senator’s chiefs of staff attended the reception honoring their former boss, that her current top aide has been with her for nearly nine years and that others have worked for her for more than two decades. “The senator is tough, fearless and passionate for the interests of Marylanders and Americans,” Sherman said.

“Barbara is authentic,” says Mary Louise Oates, who wrote two Washington thrillers, “Capitol Offense” and “Capitol Venture,” with Mikulski in the 1990s that featured a gutsy, working-class congresswoman from Pennsylvania. “And she is authentically Democrat. She is a product of Catholic schools and brings the Vatican II concern for social justice to every aspect of her legislative life.”

Still, if numerous anonymous Capitol Hill staffers are to be believed, Mikulski is one of the toughest lawmakers to work for. Washingtonian magazine calls her a “perennial” in the “meanest” member category. Even among her ideological allies, Mikulski can be considered grating, and she has been known to end an interview if she doesn’t like a reporter’s questions.

In the early ’90s, while covering Congress for the Orlando Sentinel, I spoke with her at length on several serious topics. But she cut me off dead the moment I asked about the women’s lavatory that majority leader George Mitchell ordered to be built off the Senate chamber so female members, like their male counterparts, would have a restroom of their own. NASA funding? Always happy to discuss it. Potty parity? Forget it. The Almanac of American Politics calls her manner “gruff and unpolished.” 

A major push for legislation to right what she considered a grievous wrong? Bring it on.

In 2009, she was a driving force behind a bill known as the Lilly Ledbetter Fair Pay Restoration Act, extending the period for filing a gender bias lawsuit against an employer.

Last year, reports Roll Call, Sen. Amy Klobuchar (D-Minn) gave a floor speech and invoked Mikulski’s battle cry directed to the “women of America: Suit up, square your shoulders, put your lipstick on. We’re ready for a revolution.”

Annie Groer is a former Washington Post and writer whose work has appeared in the New York Times, Town & Country and More magazine. She is working on a memoir.