What Mr. Howells said of the American theater is true of the whole American attitude toward life. “A tragedy with a happy ending” is exactly what the child wants before he goes to sleep: the reassurance that “all’s well with the world” as he lies in his cozy nursery. It is a good thing that the child should receive this reassurance; but as long as he needs it he remains a child, and the world he lives in is a nursery-world. Things are not always and everywhere well with the world, and each man has to find it out as he grows up. It is the finding out that makes him grow, and until he has faced the fact and digested the lesson he is not grown up — he is still in the nursery.

Edith Wharton (1862-1937) American novelist

French Ways and Their Meaning, ch. 4 “Intellectual Honesty” (1919)
    (Source)

Commenting on William Dean Howells' comment to her on American taste in theater and drama: "What the American public wants is a tragedy with a happy ending."