Complex sentence: After the closing of the Indian residential schools, which operated from the 1870s to 1996 and held some 150,000 aboriginal children over the decades, some former students made allegations of physical, psychological, and sexual abuse and neglect.
Split into simpler sentences: After the closing of the Indian residential schools, which operated from the 1870s to 1996 and held some 150,000 aboriginal children over the decades. Some former students made allegations of physical, psychological, and sexual abuse and neglect.