Sen. Barbara Mikulski (D-Md.). (Chip Somodevilla/Getty Images)

When Barbara A. Mikulski, then a congresswoman from Maryland, kicked me out of a caucus meeting, I was embarrassed but not offended. It was an exciting time for a young woman to work in Congress. I couldn’t believe I was even there.

Now a senator from Maryland, Mikulski, the last original member of the Congresswomen’s Caucus, is retiring. She was the champion of numerous pieces of legislation that helped women, including the Violence Against Women Act, for which Vice President Biden, a former senator, gives her much credit.

Mikulski, the longest-serving woman in Congress, was elected to the House in 1977. In 1986, she was the first woman elected to the Senate who was not a widow or daughter of a senator. She’s a former social worker and Baltimore City Council member. At 4 feet 11 inches, Mikulski is a fierce advocate for women and children who describes herself as getting “emotional, angry, outraged and volcanic.” Once you have met her, she leaves a lasting impression.

I first experienced Mikulski’s booming voice and presence when I staffed meetings of the Congresswomen’s Caucus in 1977. I was only 27, and I worked for Shirley Pettis, a moderate Republican from California who wanted to support the caucus. When she could not attend meetings, she sent me.

I represented Pettis at exactly two meetings until Mikulski ejected me so her colleague Barbara Jordan (D-Tex.) could smoke in private. Mikulski sternly and loudly reminded me, “This is a meeting of members of Congress. You need to leave.”

A historic 18 women were elected or reelected to the 95th Congress of 1977-1979. While several congresswomen attempted to form a caucus before 1977, it was met with resistance from senior members who did not want to alienate their male colleagues.

When those members retired, Elizabeth Holtzman (D-N.Y.), Margaret M. Heckler (R-Mass.), Shirley A. Chisholm (D-N.Y.) and Mikulski organized the caucus.

To emphasize its bipartisan nature, the Congresswomen’s Caucus was co-chaired by Holtzman and Heckler. The partisan rancor that now permeates Congress was not present then. Members and staff of both parties were friends and worked together.

These congresswomen met in H-235, a small room northeast of Statuary Hall normally reserved as the “Congresswomen’s Retiring Room.” The room was used as both a respite for female members and the location of the only women’s bathroom near the floor of the House. It had “toes up” cots so congresswomen could rest during long vote sessions, away from the demands of their staff.

It took until 2011, with 76 women in Congress, for the women to get a restroom of their own near the speaker’s lobby in the Capitol.

Three Republican congresswomen initially would not join the caucus. The country was battling over the Equal Rights Amendment, and they were concerned that their constituents would not approve of them joining a women-only group. Congress was also fighting about funding abortion for poor women through Medicaid.

The Congresswomen’s Caucus lobbied colleagues to extend until 1982 the time period in which states could ratify the ERA. Although the ERA was never ratified, this effort set the stage for numerous pieces of legislation to be introduced to prohibit discrimination against women.

By the time Mikulski moved to the Senate in 1987, the caucus had changed its name to the Congressional Caucus for Women’s Issues and opened membership to men. The number of women elected to Congress declined, and conservative congresswomen did not want to be at odds with the Reagan administration. Inclusion of men was seen as a way to raise more membership funds and to broaden the base of support for women’s issues.

In 1991, H-235 was renamed the Lindy Claiborne Boggs Congressional Women’s Reading Room. In 1995, Republican leadership eliminated funding for caucuses. The Congressional Caucus for Women’s Issues created Women’s Policy Inc., a nonprofit group that serves “as a resource for the women Members of Congress and their staff.”

Mikulski once said, “I think leadership is creating a state of mind in others.” My experience in 1977 of being around strong, smart female leaders, especially Mikulski, stayed with me and inspired me to run for Congress in 2000. I won a bitterly contested primary and in the general election lost by less than one point against a longtime incumbent, giving my campaign the distinction as one of the five closest races in the country.

Today, 104 women serve in Congress. And they all owe thanks to Mikulski for helping to lead the way.

The writer, a Democrat, is a former congressional staffer.