Then in 1945, the Burlington Lines railroad company published a small souvenir booklet, “Westward the Course of Empire,” subtitled “The Story of the Pony Express, Forerunner of the Burlington Zephyrs.” This booklet mentions a preference for orphans. It reproduces the fabled newspaper notice. An expensively produced monograph of only fifty-seven pages, the booklet was illustrated with elaborate linecut drawings. It was written by Gene Morgan, about whom nothing is known. Where he got the orphans information is a mystery. The publisher in Chicago-Lakeside Press, a division of the printing giant J. R. R. Donnelley-has no record of the book. It may possibly date from what is the oldest known and perhaps the first mention of a preference for orphans by the organizers of the Pony Express. That mention appears in the October 1923 issue of Sunset magazine, a popular western periodical founded in 1898 by the Southern Pacific Railroad, which variously published works by Mark Twain, Jack London, Bret Harte, Zane Grey, Dashiell Hammett, and Sinclair Lewis. In an article written by John L. Considine titled “Eleven Days to Saint Joe!” Considine attributes (as did Mabel Loving) the origin of the Pony Express ad to Bolivar Roberts.