Condition Continued: Scrolling through the others, I came upon only a few minor spots. There is tanning on the rear side of the last blank rear end paper, something may have been left sitting inside there. I didn't see any conspicuous creasing. There aren't any markings. No attachments of any kind. And no one has written their name or anything else anywhere.  All of the illustrations are in excellent shape.
I've always had the dust jacket in a fitted protective cover. The jacket looks pretty clean, perhaps a little soiling above the cousin's heads on the front cover. There is light loss at the spine ends and corners, a tiny one at the bottom edge of the rear cover as well. There's also a thin tear/loss along a part of the juncture between the spine and rear cover (third photo) and another thin one just off the top edge between the front cover and spine (first photo). A sliver of loss at the front top edge is also visible, and there is a fair amount of scuffing at the middle edges. All in all, though, as I think you can see in the photos, it presents quite nicely, not at all badly for a sexagenarian jacket from the genre of children's books. It is recommended for children between the ages of 8 and 12. The jacket flaps are in very decent shape, a slight bit of toning, a teeny tiny loss at the top edge of the rear flap, not too much bigger than a speck.

Harper &  Brothers, New York, 1956. Hardcover in Dust Jacket. Stated First Edition. Written by Evan Commager. There are a number of illustrations by N. M. Bodecker ('He is probably best remembered for illustrating Edward Eager's book series Tales of Magic, but he also illustrated works by Charles Dickens and periodicals including Harper's Magazine, The Saturday Evening Post, and the New York Times. His original drawings for children's book are housed by the Kerlan Collection at the University of Minnesota'). 
The book is quite rare. Here's what the front flap imparts: 'Set in the South in the period following the First World War, this is the story of a romantically intriguing Search for a Lady. While rummaging in the attic one day, ten-year-old Margaret (Mark) Kendall and her cousin Debbie find a cryptic letter in the pocket of their grandmother's wedding dress. It is signed Felicity, and the message bids good-by to the bride. With Bill Bradford, a 'practical cousin' from New York, the two found the Felicity Club. Its purpose is to discover everything possible about the mysterious lady who left town so many years earlier, just before her best friend's wedding. As Mark and Debbie and Bill grow up, other activities take up much of their time. But the search for Felicity is never forgotten it's wonderful and inevitable conclusion is all that anyone could possibly have hope for. Each of N. M. Bodecker's charmingly humorous pictures perfectly portrays the fun and warmth of the story.'