I'm halfway through "Annie's Ghost", a well-written, very interesting book (2009) by a journalist who discovers, after his mother's death, that she had a sister no one in his family knew about. His vast research in both Michigan and elsewhere reveals his aunt was born with a bent leg, in addition to possible cognitive limitations. Since this era was back in the 1920's - 1940's or so, he had to find extended relatives who are now in their 80's and 90's to explore this "secret" held tightly by his mother and why she may have done so.
The author raises the topic of family secrets - why they existed and explores the memory of relatives who were just kids when they overheard hushed parts of conversations, only to secure the secrets themselves; he researches how society treated "crippled" people during that time.
Unfortunately, the civil rights movement for the disabled didn't come into focus until the early 1970's.