All of the times that Flannery O’Connor mentions Carson McCullers in her letters collected in The Habit of Being: Letters of Flannery O’Connor:

I read in the paper that Carson McCullers is going to have a play shortly to be called The Square Root of Wonderful—a title that makes me cringe. (8 Oct. 1957)
…Paul Levine [is] preparing a book on 6 writers—McCullers, Capote, Buechner, Bellow, Salinger, and me… (25 June 1960)
I haven’t read [Frederick] Buechner myself, but if I was writing it I would throw out Capote in favor of Malamud and Carson McCullers in favor of [J.F.] Powers. (9 July 1960)
Last week Houghton Mifflin sent me a book called Clock Without Hands by Carson McCullers. This long-awaited-by-the-faithful book will come out in September. I believe it is the worst book I have ever read. It is incredible…It must signal the complete disintegration of this woman’s talent. I have forgotten how the other three were, but they were at least respectable from the writing standpoint. (26 July 1961)
If you ever go to the Albee-McCullers [play] let me know what you think about it? … Did you ever consider Wise Blood as a possibility for dramatizing? If the times were different I would suggest that, but I think it would just be taken for the super-grotesque sub-Carson McCullers sort of thing that I couldn’t stand the sight or sound of. (5 Nov. 1963)
I was interested in the reviews of the Carson McCullers adaptation. I dislike intensely the work of Carson McCullers but it is interesting to see what is made of it in the theatre, and by Edward Albee at that. (28 Nov. 1963)
