This was done by families to female relatives who the relatives thought hopefully promiscuous, by mental institutions to prevent “mental defectives” from reproducing. The procedure was typically disguised as an appendectomy to the patient. Apparently it tended to be more common in Mississippi. Hence the name, but it was a practice that existed in other states as well. This is different from the court ordered sterilizations where the victim was aware of the procedure. However, the pseudoscience of eugenics was the rationale behind both.