6-1/8x8" handwritten single-sided letter on unlined paper is dated May 18, 1958 and is addressed to woman who sent celebrated children's author/illustrator Sendak a very sweet fan letter, mentioning Ruth Krauss's book "Charlotte And The White Horse" book, for which Sendak provided the illustrations. Letter has ragged top margin as produced and horizontal fold at center. Slight ink smudge to a word in last paragraph, but all text remains legible. Back of letter is half covered in child's ink scrawlings. These show slightly on letter side as lines in paper. Letter still displays VF. Comes w/original mailing envelope w/has extensive ink scribbling by child and just comes along. Lot also includes 5-3/8x6-5/8" hardcover of "Charlotte And The White Horse," published by Harper & Brothers, ©1955. This book was one of Sendak's early works and he has signed first blank inside page "To Jonathan -" in black ink and added nicely done sketch of sitting dog w/"Hello" word balloon. Sendak has signed below this. Book's cover has moderate age spotting and is VG overall while pages remain clean, as does page w/inscription/sketch/signature. Comes with Hake's COA.