When she died in December at the age of 84, Debbie Reynolds was remembered as one of the last great stars of Hollywood’s studio era, when singing-and-dancing talents were plucked out of obscurity as teenagers, signed under contract to the studio, and turned into stars by a mighty studio machine. But Reynolds, in fact, joined the system at the very end, and was one of the last stars created by MGM before the once-mighty studio declined in the 1950s. With Reynolds gone, the number of stars who knew MGM at its mightiest grows ever-smaller. Over the next five weeks, we’ll be sharing interviews with those stars who remember MGM at its best—and how it fell from grace.

Margaret O’Brien was only three years old on the set of her first MGM film, Babes on Broadway, but it made an impact: “I remember Mickey saying, ‘Hello, the cute little girl!’ ” she remembers now.

Mickey Rooney himself was only 21, but had already made 135 movies, including shorts, over 15 years. For his generation of child actors, working hours and education were mostly at the studio’s discretion. MGM built a white plaster and Mediterranean-tiled school house on the studio lot, where young contract actors—Elizabeth Taylor, Lana Turner, Garland, Rooney, and others—studied together in one room.

By the time O’Brien reached school age, child-labor laws were better enforced. “I had a private tutor, in my own dressing room on the lot, but I would go into the school for playtime,” O’Brien remembered.

Movies about children were big business, especially at MGM. The studio specialized in adapting Victorian novels like Little Women, Jane Eyre, and The Secret Garden, using O’Brien and a stable of young actors, many of whom were being groomed for grown-up stardom. Elizabeth Taylor turned 18 on set of Little Women. As a younger star, O’Brien remembers, “[Taylor] used to have her animals—all her little chipmunks—and loved playing with them.” But by the time they worked together on 1949’s Little Women, “she didn’t have to have the school teacher following her every minute, saying, ‘Time for school!’ So she was able to have a little crush on [co-star] Peter Lawford, without the school teacher standing right next to her.”

O’Brien, on the other hand, was still only 11, and closely watched. Work ended promptly at six P.M. “Even if I wanted to finish a scene, because I didn’t want to do it the next day, the school teacher would say, ‘No, six o’clock!,’ and even the studio executives were afraid of the school teachers.”

Judy Garland came of age in another of Margaret O’Brien’s movies, 1944’s Meet Me in St. Louis, director Vincente Minnelli’s lavish re-creation of Sally Benson’s turn-of-the-century family stories. Garland, 22 by the time the film opened, was engaged to Minnelli; the ruby-red lips and luscious auburn hair she displayed in the film were a contrast to Garland’s previous roles as a sweet, small-town girl. “But this was the first one where she said she felt beautiful,” O’Brien remembered.

In spite of Garland’s transformation, seven-year-old O’Brien was still the studio’s priority. Before filming, O’Brien’s mother approached Louis B. Mayer, asking for the studio’s top salary—$5,000 per week—for her daughter. At first, Mayer refused, threatening to put a look-alike girl, already under contract, into O’Brien’s role instead. O’Brien and her mother stood their ground. They left Hollywood for New York, waiting for Mayer to reconsider.

“Of course, the studio brought me back and said, ‘Oh yes, Mr. Mayer said absolutely, we’re going to give you the $5,000 a week.’” O’Brien said. Incredibly, it was the same salary that 22-year-old Garland was getting on the movie. At the 1945 Oscars, O’Brien received the Juvenile Award for Outstanding Child Actress for her work in the film—the same award Garland received for The Wizard of Oz, in 1940.

Unlike Garland, O’Brien didn’t get to “grow up” at MGM. By the time she reached her teens, in the early 50s, the studio was floundering financially, and Dore Schary had replaced Mayer as head of production. Elaborate Victorian adaptations were also on the wane, as Schary tried to recoup the studio’s losses. “You did see a difference because it was a little bit more of an unhappy time at the studio. It was somebody trying to bring it back, so it wasn’t the joy that the studio projected, when I was there earlier,” O’Brien said.

Like many other contract movie players, O’Brien made the transition to TV, then a budding medium. Still, her career continued to be defined by the early years at MGM, which were more mature than one might think. “At MGM there was no nonsense,” O’Brien said. “They treated us really as actors and actresses, like they did the adults. They didn’t baby us or talk to us in baby talk or anything, which we would not have liked at all. They talked to us as adults, saying, ‘That scene wasn’t so good, Margaret. Can you do it a little bit better? Can you make it a little bit this or that?’ And that’s the way we would work—very much like I would do today.”