The real Mary Amelia Ingalls (1865-1928) lost her sight due to viral meningoencephalitis and not scarlet fever as once thought. She did attend a school for the blind for seven years in Iowa, then lived with her parents until their deaths. She then lived with her sister, Grace Pearl Ingalls Dow and then with her sister, Caroline Celestia "Carrie" Ingalls Swanzey until Mary's death from complications from a stroke and pneumonia. Mary helped support the family by making fly nets for horses. She never married.
Mary Amelia Ingalls (January 10, 1865 - October 20, 1928) had an illness at the age of 14 that was thought to be scarlet fever. However, based on firsthand accounts, school registries, newspaper reports of Mary's illness as well as epidemiological data on blindness and infectious diseases, a 2013 study published in the journal of Pediatrics concluded that it was viral meningoencephalitis that caused Mary's blindness.
Mary attended the Iowa Braille and Sight Saving School in Vinton, Iowa. She finished a seven-year course of study in 1889 and graduated.
In 1997, the TV Guide jointly ranked this episode and I'll Be Waving as You Drive Away: Part II (1978) number 97 on its "100 Greatest Episodes of All Time" list.
At age 15 when this episode aired Melissa Sue Anderson was the same age as Mary Ingalls when she lost her sight