Until last January the public had never seen Leslie Uggams in pain or crying or fighting or losing. No one thought the saccharine voice and scrubbed face that had been around almost as long as television, had what blues singers call "tailfeather" - the knack of reaching the scream, the emotional marrow.

Then along came "Roots." As Kizzy, the daughter of Kunta Kinte and the mother of Chicken George, Uggams survived a kidnapping, a rape and many other forms of dehumanization; demonstrated love, arrogance and wit. Uggams also showed that talent had been there all the time.

"People now look at me with different eyes. I am now being taken more seriously as an actress," says Uggams, showing the scars still on her arms from the tougher scenes. "Kizzy became part of my life."

In her 34 years, 28 of them in show business, Uggams says she has never felt so good. Truly, she has never been so much in demand. This week she is appearing at the Carter Barron Amphitheater in an all-black version of "Guys and Dolls."

And until now Uggams was never quite sure what her slot was. She's at a professional passage, not only waiting to find out if she wins an Emmy next month of Kizzy, but waiting for a good part, proof that her dramatic acting wasn't a fluke.

"The problem now is finding the role," she says, agitated that there are more good black actresses than good parts. "I do so many things - night-clubs, musicals and musical television. Now I want to do more acting. Now I understand the problem gifted actresses, like Cicely Tyson, are talking about . Everyone, everyone went out for "King" (the television movie based on the life of Martin Luther King Jr.), but I didn't make it.

But in a way I was grateful I could try."

The waiting times are not idle times. The week after "Roots" attracted the largest television audience in the industry's history, and Uggams became the object of emotional fan letters, she and her husband. Grahame Pratt, filed for bankruptcy. "I was not broke. I just want to get out of some legal hassles and that was the way to do it," says Uggams. The public's reaction was touching. Uggams says: She received hundreds of calls and offers of money and housing.

Work that's routine but enjoyable to Uggams also fills the meantimes. She appeared on the Frank Sinatra special this spring. And this summer she has played Sister Sarah Brown, the fervent but romantically cautious missionary of "Guys," in Las Vegas, Dallas, Houston and St, Louis.

"I really thought about the role, wondering if it could work with a black actress. I decided when if you were Japanese you could bring your own experience to the part. And I chosen Sarah because she was challenging. You have to work harder to bring the oomph out." says Uggams, her voice almost a whisper until she laughs. Then she's good and loud. Onstage she is the professional, clear and tranquil, despite the mosquitoes and the bees bargaining for room under the lights. Backstage she is reading 'The Thorn Birds," by Colleen McCullough.

Stride, that's what Leslie Uggams has in her personality, that's what she has maintained in all career.

"I am really one of those take-each-day-as-it-comes persons," she says, leaning her elbows on a desk in her hotel suite. She is wearing a cross-shaped diamond ring that covers two knuckles - designed by her husband. Her heart-shaped face glistens naturally and her enormous eyes, her most animated feature, move constantly.

Because everyone in her family was a star, at least in their poor Washington Heights neighborhood, Uggams says the spolied child-star syndrome never happened. Her father, who worked as an elevator operator and floor waxer, also sang with the famed Hall Johnson Choir. Her mother, a waitress when she wasn't chaperoning her daughter, worked briefly as a Cotton Club dancer. An aunt, Eloise Uggams, appeared in every version of "Porgy and Bess" expected the original.

"That all brought me down to earth. I might have been on 'Beulah," but I got an allowance, I went to the super-market, I did the laundry," she says. She starred with Ethel Waters on 'Beulah' at age 6, did some other local television and performed at the Apollo when she was 8 as a warm-up act for Ella Fitzgerald, Dinah Washington and Louis Armstrong.

At 15 she got her big break. She appeared on "Name That Tune", winning $25,000, and the attention of Mitch Miller, the bandleader. Then she made her make in television history. She became the first black regular on a network show, "Sing Along With Mitch."

Now, looking back at the wasteland television was for blacks in the early 60s, Uggams says. "They wanted a black girl who could sound white. I knew how to do it. It was necessary for me at the times. But, more importantly, I am grateful to Mitch Miller because the Southern stations didn't want the show with me in it. He said: If Leslie goes, we all go. He was a white man who put his livelihood on the line."

In her own short-lived variety show, Uggams provided the formula for the black situation comedies that have provided most of the last few years. Her sketch of a family from "Sugar Hill." a legendary section of Harlem, was a forerunner.

"The 'Good Times' formula came from us. They ripped us off," she says, not begrudingly but determined to set the record straight. "But another thing is that we had a black writer, the same John Amos of "Good Times," a black choreographer, Donald Mac Kayle, a black musical director and apprentice cameramen. We wnt through hell to get that. I had to fight to wear an Afro," says Uggams.

Uggams won a Tony Award for "Hallelujah, Baby." But she is visibly excited about the Emmy prospects. "My mother says, what's for you, you will get.' But if I won for Kizzy, that would mean I have been received as an actress.