Ellie Kemper is apologizing after photos of her being crowned as queen of a ball with ties to white supremacy as a teenager. The Unbreakable Kimmy Schmidt star, 41, said she didn’t know the history of St. Louis’ Veiled Prophet Ball when she decided to participate.

“Hi guys – when I was 19 years old, I decided to participate in a debutante ball in my hometown. The century-old organization that hosted the debutante ball had an unquestionably racist, sexist, and elitist past,” she began her post on IG.

Kemper explained that she was “not aware of the history” at the time but that “ignorance is no excuse.”

“I was old enough to have educated myself before getting involved,” she said.

The Ball was created in 1878 to honor the ritual of Mardi Gras, and is associated with white supremacy.

Several bold-faced names, including Katie Couric, Mindy Kaling, Alec Baldwin and Rob Delaney, posted messages of support, in words and heart emojis.