The day I got cast as Nellie Olesen on Little House on the Prairie was the best day of my life,” Alison Arngrim, 53, enthuses to ‘Closer.’

The actress, who was 12-years-old in the spring of 1974, initially auditioned for the roles of Laura or Mary Ingalls, with no luck.

“A few weeks later, I got called to come back and read for Nellie. I remember thinking how awful this girl was, but she just came naturally to me,” she admits.

alison arngrim

Alison on ‘Little House on the Prairie.’

During Alison’s audition, her portrayal of spoiled Nellie made the show’s star Michael Landon laugh so hard that he cried.

“I think it was when I was going on about having three sets of dishes that landed me the job,” she says.

Related Story: The Cast of ‘Little House on the Prairie’ Reunites to Celebrate the Show’s 40th Anniversary!

“Less than 30 minutes after I left the studio, I got a call that I not only got the part but that my wardrobe fitting was the next week,” she recalls.

To read the full story on Alison, pick up the new issue of ‘Closer Weekly,’ on newsstands now!