Transcript for Joan Rivers: A Look Back At Comedienne's Storied Career
Turning, now, to what will forever be Joan rivers, the final chapter. Even for one of the hardest working women in Hollywood, it was arguably one of her most successful and productive periods. So, how does she do it? Tonight, we look at a pioneer who never shroud down. Constantly in motion. Joan reinvented herself creatively and often physically. A fresh face, getting even fresher. At 75 -- You are a piece of . And you're a stupid blonde. Reporter: An age when most are already retired. I don't want to hear -- Reporter: Joan rivers rere-ignited her career, on "Celebrity apprentice." You really are a role model for so many people. Joan, congratulations. Reporter: It launched the final chapter of a storied career. And made her a star for a new generation, who never heard of the pioneering comedienne. I'm back, you bastards. Reporter: We talked to Donald Trump a short time ago. She beat out a lot of powerful people. And strong physically people. She considered that one of the most important things she had ever done. 40 years in the Business and this is where you end up. Reporter: Once back in the spotlight, she wasn't going to give it up again. Tony nominations. Reporter: She beard her private life in an award-winning documentary called "Joan rivers: A piece of work." About her lifelong ambition. This is not a full book. Reporter: She was painfully honest about the insecurities that drove her to fame. I'll show you fear. That's fear. If my book ever looked like this, it would mean that nobody wants me. Everything I ever tried to do in life didn't work. Reporter: On display, every, single joke, for over 30 years. Categorized and filed for future use. Why should a woman cook, so a husband can say, my wife makes a delicious cake to some hooker. Rivers helped change the perception of women in comedy, setting the stage for a generation of female comics. I'm an artist. I'm doing it for the art, like you are. Reporter: Rivers was constantly in motion. At 81, she showed no science of slowing down. Look at what was her upcoming schedule. 25 appearances between now and November 22nd. Living up to her promise that she would never retire. America needs Joan rivers. I will not retire, do you understand me? I plan to be around for the next 100 years. And god bless America. These two on the red carpet, back at the trailer park, making the next one. Reporter: She turned out a weekly show for E! "Fashion police," ever ruthless to the starlets she deemed fashion offenders. As a dress, I hate it. It's something to wash the bird Off my car. Reporter: Her celebrity takedowns garnered the most attention. Like on "The graham Norton show" when she tore into Angelina Jolie. Oh, Joan, we don't know which children are adopted and we don't know which are ours personally. They're all the same. Isn't that right, Billy and sally and jimmy and little magumba. Isn't that right? Anyone that has to stop me and say, why did you say that? Then you know, we wouldn't be friends. You didn't respond to me. Reporter: But the stars got one recent Chang at revenge, with the A.L.S. Ice bucket challenge. Just do it. Just do it. Let's get the whole damn thing overwith. Do it. Reporter: The stars of the internet are usually youngsters. But Joan rivers was able to harness 2.1 million Twitter followers. Tweeting just weeks ago, I'm definitely going to watch the emmys this year. My makeup team is nominated for special effects. With Joan, there was nothing offlimits. At 79, she invited cameras to show private moments with her daugt and grandson on her reality show. I'm bored. You know, cooper, there's a thing called the will. W-I-l-l. I know how to spell. And you know what it means, too. Reporter: She brought cameras into her bedroom, with her online show, "In bed with Joan." I was told you died like ten years ago and you're animatronic. I don't know how you're working this. It's amazing. Reporter: Offstage, Joan had a devotion to the needy of New York City. The cause she championed on "Celebrity apprentice," in god we deliver. The amount of volunteers. How did you start? I started at 8. Reporter: The organization was initially devoted to helping AIDS patients, for Joan, a personal cause. We put tiles up with names of friends who have died of AIDS. And I think I bought the fourth tile for the wall. There's my first friend who died of AIDS. That's why I work for god's love. Reporter: The hallmark of rivers' career, taking the hardships of life and turn them into celebrating, something worth laughing about. I was called so-called retirement. Yes. And there may be somebody who wants to know about yours. I cannot retire. Okay. I have two new faces on layaway. And I -- Reporter: And for that, she remains unforgettable. Joining us now are Barbara Walters, a long-time friend of Joan rivers. Barbara, thanks for being with us. She was joking in that clip about never retiring. That wasn't really a joke. She never planned to retire. She would rather work than do anything. If there were three people in a room, she would perform for them. And you know, it's funny. But she would be thrilled to know that she was getting this worldwide outpouring of love these past few days. And a lot because of "Fashion police. "She had a whole, new generation of people who fell in love with her. I'm going to miss her humor. I'm going to miss her gossip. I'm going to miss our dinners together. Thanks, Barbara, for sharing your memories and adding to the tributes coming out today.
This transcript has been automatically generated and may not be 100% accurate.