Undated (AP) _ A year ago, Carol Moseley Braun was a face in the crowd at the gloomy, gray county building in Chicago. Today, she stands in the spotlight with a one-of-a-kind title: the first black female U.S. senator.

The 45-year-old Democrat, whose stunning primary win helped fuel the ''Year of the Woman'' in politics, added her name to the history books by beating Republican Rich Williamson, a lawyer and former Reagan White House aide.

Braun entered the McCormick Place hotel grand ballroom - the same room used by Harold Washington when he was elected Chicago's first black mayor - to cheers of ''Carol 3/8 Carol 3/8 Carol 3/8''

''It is a new day in America. We have won a great victory tonight, and you, you have made history,'' Braun told about 400 supporters.

''You have shown what we can do when we come together when we stop them from dividing us along race lines and gender lines,'' Braun said. ''I'm going to work hard to be the very best senator Illinois has ever had.''

Braun's rise from obscure government bureaucrat - Cook County recorder of deeds - to a star on the Democratic horizon began in March when she handed Sen. Alan Dixon his first loss in four decades in a three-way primary.

After that, her candidacy became a cause. She was toasted from Washington to Hollywood, millions of dollars poured into her campaign, and her dazzling smile was everywhere - from news magazines to Vogue and Essence.

''She became a media star,'' said David Bositis, an analyst at the Joint Center for Political Studies in Washington. ''She evokes the memory of Anita Hill and the notion it's time to put an end to all white-male politics.''

Braun, an attorney, launched her campaign after watching Hill's harsh questioning during the Senate Judiciary Committee's confirmation hearings of Supreme Court Justice Clarence Thomas, whom Dixon supported.

Braun basked in her celebrity halo until the final weeks of the race, when she was dogged by a Medicaid investigation involving her mother, Edna Moseley, a nursing home recipient.

The state had investigated a $28,750 inheritance Mrs. Moseley had distributed to her three children. That extra income should have been reported to officials. Braun resolved the matter, paying more than $15,000 the state said it was owed.

A divorced mother of a 15-year-old boy, Braun drew strong support from feminists and liberals who approved of her reformer's agenda during her 10 years as an Illinois lawmaker.

As the first black woman senator, Braun will be scrutinized.

''A lot of attention will come to her because she is a symbol of hope,'' said Ronald Walters, chairman of the political science department at Howard University.

''She'll find people looking over her shoulder in this town,'' he said. ''Many of those expectations she faces will be unreasonable.''