Mary Amelia Ingalls, the older sister of Laura Ingalls Wilder, was just 14 years old when she lost her eyesight. Her sudden blindness was a life-altering event that deeply affected the Ingalls family and became a major storyline in Laura’s Little House books.
Mary’s illness and its impact on her life have fascinated readers and historians for decades. While the books describe her condition as a result of scarlet fever, modern researchers believe her symptoms suggest a different medical cause.
According to Laura Ingalls Wilder’s own account in By the Shores of Silver Lake, scarlet fever was the illness that caused Mary’s blindness. At the time, this was a common diagnosis, and scarlet fever was known to cause severe complications in children, including vision loss, hearing problems, and even death.
However, recent medical research has raised doubts about this explanation. In a 2013 study published in the journal Pediatrics, doctors reviewed historical records, family documents, and contemporary newspaper articles. They concluded that Mary likely suffered from viral meningoencephalitis, an infection that causes inflammation of the brain and its surrounding tissues.
Newspaper accounts from the time described her condition as a “brain fever” or “a stroke”, with reports of facial paralysis and neurological symptoms—details more consistent with meningoencephalitis or a related viral illness than with scarlet fever.
Mary Ingalls’ Life Before and After Going Blind
Mary Ingalls was born on January 10, 1865, in Pepin County, Wisconsin, and grew up traveling with her family across the American frontier. When she was 14, while the family was living near Walnut Grove, Minnesota, she became seriously ill. Her condition progressed rapidly, and she eventually lost her sight completely.
Despite the challenges of adjusting to life without vision, Mary remained a bright, gentle, and determined young woman. Two years after losing her eyesight, in 1881, she enrolled in the Iowa College for the Blind in Vinton, Iowa. She was 16 years old when she began her studies there.
Education at the Iowa College for the Blind
The Iowa College for the Blind, now known as the Iowa Braille and Sight Saving School, provided Mary with an opportunity to continue her education and learn important life skills. She studied subjects such as:
Braille reading and writing
Mathematics
Music and piano tuning
Domestic skills, including sewing and beadwork
Mary spent seven years at the school and graduated in 1889, returning to live with her family in De Smet, South Dakota. She remained close to her parents and sisters throughout her life and helped around the house using the skills she had learned at school.
Mary Ingalls in the Little House Books vs. Real Life
In Laura Ingalls Wilder’s Little House series, Mary is portrayed as the dutiful, kind, and responsible older sister, often admired by Laura. Her blindness is presented as a pivotal moment in the family’s journey and a source of emotional strength and unity.
However, the books do simplify and soften some of the real-life details:
The cause of Mary’s blindness is attributed to scarlet fever, which modern research disputes.
The emotional and financial burden on the family to send Mary to school is minimized in the books, although in reality, it required sacrifice and support from extended family and the local community.
Mary’s experiences as a blind adult—her challenges, hopes, and limitations—are largely absent from the later books.
Despite this, Laura’s portrayal of Mary helped raise awareness of the challenges faced by individuals with disabilities during the 19th century and offered a rare early depiction of a blind character in children’s literature.
