“I’ve enjoyed fighting the Republicans, quite frankly,” Rep. Cardiss Collins (D-Ill.) said when she decided not to run for reelection in 1996. (Tom Allen/The Washington Post)

Cardiss Collins, an Illinois Democrat who reluctantly filled her late husband’s seat in Congress in 1973 and over the next quarter-century became one of the most prominent black women on Capitol Hill, died Feb. 3 at Inova Alexandria Hospital. She was 81.

A family friend, Mel Blackwell, confirmed her death and said she had complications from pneumonia.

Rep. Collins was elected to Congress in a special election six months after her husband, congressman George W. Collins, died when a commercial jetliner on which he was a passenger crashed near Chicago’s Midway airport, killing more than 40 people. The widowed mother of a young son, she agreed to seek election only at the insistence of Richard J. Daley, the powerful mayor and Democratic kingmaker.

Once elected, Rep. Collins learned the labyrinthine world of Capitol Hill and rose to serve as chairwoman of the Congressional Black Caucus (CBC) and as her party’s whip-at-large. Her legislative portfolio centered on women’s and minority rights.

By the time she stepped down in 1997, she was the longest-serving black woman in Congress. For a number of years on the Hill, she was the only black woman serving in the House.

Rep. Collins overcame her natural timidity to become a forceful political voice. “We will no longer wait for political power to be shared with us,” she said at the beginning of her two-year leadership of the CBC in 1979. “We will take it.”

She sparred with adversaries in both major parties. At the outset of her leadership of the CBC, she declined to invite President Jimmy Carter, also a Democrat, to speak at a high-profile caucus fundraiser.

When questioned about the political wisdom of snubbing the president, she was insistent.

“He has nothing to say; that’s my personal view,” Rep. Collins told The Washington Post at the time. “He has traded off black votes given to him in confidence. When he calls these summits, he ignores the Black Caucus. What about respect for our offices?”

In 1993, during an emotional debate over the ban on federally funded abortions for poor women, she sparred with Rep. Henry J. Hyde (R-Ill.), the champion of the ban.

In a dramatic confrontation, Hyde said from the floor: “We tell poor women, ‘You can’t have a job, you can’t have a good education, you can’t have a decent place to live. I’ll tell you what we’ll do. We’ll give you a free abortion because there are too many of you people and we want to, kinda refine, refine the breed.’ ”

Rep. Collins rushed to a microphone and responded, “I’m offended by that type of debate.”

Hyde replied that he would “direct my friend to a few ministers who will tell her just what goes on in her community.” He later apologized to Rep. Collins.

Jaime Dominguez, a lecturer in political science at Northwestern University, said in an interview that one of Rep. Collins’s signature achievements was “leveling the playing field for women and minorities.”

She was credited with spearheading legislation that required colleges to disclose spending on men’s and women’s sports. She was an outspoken critic of standardized college entrance exams — which she considered racially and culturally biased — as criteria for athletic eligibility.

Rep. Collins passed a bill designed to fight “redlining,” a racially discriminatory practice by insurance companies, and called on government agencies to more aggressively hire minorities.

On health issues, she promoted medical research on illnesses afflicting minorities and women, helped expand Medicare coverage for mammograms and helped win recognition for October as National Breast Cancer Awareness Month.

Rep. Collins did not seek reelection in 1996 and was succeeded by Danny K. Davis, a Democrat. She denied suggestions that she left because Democrats were no longer in the majority after the Republican Revolution two years earlier. “I’ve enjoyed fighting the Republicans, quite frankly,” she said.

Cardiss Hortense Robertson was born Sept. 24, 1931, in St. Louis. She received a bachelor’s degree from Northwestern University in 1967 and was an auditor for the Illinois Department of Revenue.

Her introduction to politics came through her husband, whom she married in 1958; she campaigned with him when he sought the office of alderman. Survivors include her son, Kevin Collins of Waldorf, and a granddaughter.

Rep. Collins once said that if she could go back in time, she would not have run for Congress. “The worst thing was suddenly looking around and discovering Kevin was a man,” she told The Post. “He had grown up without me.”

She also reflected on her accomplishments.

“I was basically an introvert, but once people learned I had something to say, I gained confidence,” she said. “But it took a long time to come out of my shell and realize I was here, doing this alone.”