USA Today contacted the South Dakota State Historical Society last week to discuss an article that was soon to appear in Pediatrics about Mary Ingalls’s blindness (read USA Today’s coverage here). An assistant professor of pediatrics at the University of Michigan speculates that the illness that caused Mary Ingalls’s blindness was probably viral meningoencephalitis—a big term that was not likely to find its way into Laura Ingalls Wilder’s books or her autobiography.
In Pioneer Girl, Wilder described the circumstances in this way: “Mary was taken suddenly sick with a pain in her head and grew worse quickly.” A few days later, one side of her face was “drawn out of shape,” and “Ma said Mary had had a stroke.” Two doctors in Walnut Grove attributed Mary’s failing eyesight to the stroke that had damaged the nerves in her eyes, which “were dying.” Wilder concluded: “They had a long name for her sickness and said it was the results of the measels [sic] from which she had never wholly recovered.”
In her fictional retelling of this episode in her sister’s life, which appears in the opening pages of By the Shores of Silver Lake, Laura Ingalls Wilder ascribed the condition to a bout of scarlet fever, one of the most deadly childhood illnesses of the nineteenth century. Pamela Smith Hill, Wilder biographer, suggests, “Wilder probably chose scarlet fever for the fictional version because it was such a deadly disease and because after arguing with Rose about whether to include Mary’s blindness in the Little House books at all, it was a swift, clear, and believable alternative.” For the age group she was writing for, scarlet fever was understandable; viral meningoencephalitis is a term best understood by medical researchers and doctors.
Nancy Tystad Koupal