Interesting. I didn't know they ever did that in America. That was thing you heard about happening in enemy conformist communist dystopias.
When my Mom was a kid in elementary school in the late 1930s/early 1940s she had a teacher who would try to "correct" Mom with a ruler. When my Grandfather heard about that, he visited the school and made it clear to the teacher and administration that his daughter would NOT be "corrected" and that she would continue to be left handed.
My Grandfather, who was also left handed, could be QUITE scary when he wanted, or needed, to be.
That ended the matter.
Odd fact about left handed in my Mom's side of the family....
One person in each generation going back at least 5 generations was left handed. Mom was the only woman.