Betty Ford is Michelle Pfeiffer's last first lady.

Pfeiffer stars in Showtime's new series "The First Lady," which documents the lives of three prominent first ladies throughout U.S. history. Pfeiffer portrays Betty Ford, wife of president Gerald Ford, as has been hailed for her performance. Despite this, Pfeiffer says she'll never play a real person again. She explained,

"I said I would never do it again. Every choice you make, and you just want to honor the person that you're playing and you want to be as authentic as possible, knowing that there will be times where you're not and you can't be. I'm never doing it again."

Pfeiffer didn't know Ford's legacy going into filming, but was nonetheless proud to portray her, and thrilled more people will see her contributions because of "the First Lady." She elaborated,

"I didn't know half of the contribution that Betty Ford made. Of course, like most people, I knew of her struggle with alcohol abuse and drug addiction, and her founding the Betty Ford clinic, but that's really kind of the extent of it. And I mean, as if that isn't enough, there's so much more to her. I'm really honored that I was given the opportunity to share that story with everyone."

Pfeiffer showcased Ford's achievements at the red carpet premiere of the series, where she said she was excited for viewers to discover "how fascinating" Ford was. She shared,

"She ran a command center in the White House to lobby for the ratification of the Equal Rights Amendment, and she talked about a lot of very hot-button subjects that were just not discussed. Breast cancer—it was shameful to talk about things, and so she saved a lot of lives."

"The First Lady" also stars Viola Davis as Michelle Obama and Gillian Anderson as Eleanor Roosevelt, and is available to watch on Showtime.