Harvey Kurtzman's Jungle Book #338 K

Full title: "Harvey Kurtzman's Jungle Book or Up from the Apes! (and Right Back Down) —In Which Are Described in Words and Pictures Businessmen, Private Eyes, Cowboys, and Other Heros All Exhibiting the Progress of Man from the Darkness of the Cave into the Light of Civilization by Means of Television, Wide Screen Movies, the Stone Axe, and Other Useful Arts"

150000 copies printed; Library of Congress catalog #59-11152 On-sale date is publication date in Catalog of Copyright Entries, 1959 Books and Pamphlets, page 1301

Could be considered an early Graphic Novel, as it is comics material created to be published in a book format (not originally printed in a magazine or newspaper strip).