<P> Actors Bonnie Franklin, Pat Harrington, Jr., and Valerie Bertinelli were the only cast members to remain with the series throughout its entire run . Lead actress Mackenzie Phillips was fired after the fifth season due to growing problems with substance abuse . She later returned in a frequent recurring role . Original cast member Richard Masur was written out early in the second season, but returned as a guest star in the sixth - season finale . </P> <P> After Masur's departure, the producers tried going in a different direction . Instead of Ann Romano being romantically involved with a man, it was decided to give Ann a comedic foil . For that role, producer Lear chose actress and comedienne Mary Louise Wilson, who had just completed a successful run on Broadway as Tessie Tura in a revival of Gypsy starring Angela Lansbury . Wilson was signed to play Ginny Wroblicki, a cocktail waitress who moves into Schneider's apartment building, and immediately becomes Ann's best friend and confidante . The shows' ratings began to decline soon after Wilson's arrival, as the character of Ginny Wroblicki proved to be unpopular with viewers . According to her memoir, My First Hundred Years in Show Business, prior to being cast as Ginny, Wilson had never seen One Day at a Time and immediately sat down and watched an episode one night in her apartment . She did not find the sitcom funny at all and was not given a script until the first read - through of her first episode . Wilson also did not get along with Franklin, "who took her role as arbiter over moral issues very seriously" and who considered herself "our foremost authority on Broadway". She also thought that Harrington's character of Schneider was not funny at all, although she liked Harrington himself, and found him hilarious offscreen . Wilson wrote that "aside from Lear, nobody thought I was funny...To make matters worse, each character, according to the show's formula, had to have a' serious' moral dilemma at some point, and I was given some problem about an illegitimate child to work out in these increasingly sentimental scenes that made my bowels shrink ." At the end of the second season of One Day at a Time, Wilson begged her agent to ask Lear to release her from her contract . Wilson later admitted, "I felt terribly wrong to be so miserable . I knew this was the kind of break actors longed for ." Wilson was also unaccustomed to working on a sitcom with four cameras in front of a live audience where "you said your line when the red light on the camera went on...and there follows a pause longer than the river Styx before the light on camera four goes on" at which the character you're speaking to says the next line . After the meeting with her agent, Wilson impulsively changed her mind and agreed to stay with the series, but it was too late . Her agent had already informed Norman Lear of Wilson's unhappiness and she was released from the show after appearing in 14 episodes . The character of Ginny Wroblicki was never seen, referred to, or heard from again except in a fifth - season episode ("Retrospective") made up mainly of clips from earlier in the series . </P> <P> For the next two seasons, the central cast of Ann, Julie, Barbara, and Schneider was supplemented by recurring characters, including William Kirby Cullen as Julie's boyfriend Chuck Butterfield, Howard Morton and K Callan as Chuck's parents, John Putch as Barbara's awkward friend Bob Morton, Scott Colomby as Barbara's boyfriend Cliff Randall, and John Hillerman and Charles Siebert as Ann's bosses, Mr. Connors and Mr. Davenport, respectively . Dick O'Neill and Nedra Volz made three appearances together as Orville and Emily, residents of the retirement home where the main characters put on a semiregular variety show . Joseph Campanella also made several appearances as Ann's ex-husband and the girls' father, Ed Cooper . </P> <P> Michael Lembeck joined the series as Julie's husband, Max, in the fifth season, but he was written out as a consequence of Phillips' firing (but later returned in season seven along with Philips). A steady stream of regulars was added in the ensuing seasons, including Ron Rifkin as Ann's boyfriend, Nick; Glenn Scarpelli as Nick's son, Alex; and Boyd Gaines as Barbara's boyfriend, later husband, Mark . Shelley Fabares, who had previously guest - starred as Ann's rival co-worker Francine Webster, appeared more frequently, eventually becoming a regular . Nanette Fabray, who played Ann's mother, also made more frequent appearances before becoming a regular cast member in the final season . Howard Hesseman joined the series for a short time as Mark's father, Sam, who would become Ann's second husband . </P>

Who played chuck on one day at a time