To determine the copyright date of Rudyard Kipling's high-seas adventure Captains Courageous, we need to know a bit about the novel's publication history. The story first appeared in serial form in McClure's magazine beginning in November 1896. It was actually quite common in that era for novels to begin their lives as serials in magazines. Imagine, though, getting caught up in an exciting story only to turn the page and find words like “Continued in the next issue” staring you in the face. You would have to wait a whole month for the next installment.
The official copyright date of Captains Courageous, then, is 1896. However, some editions of the novel print the copyright as “1896, 1897.” The second date refers to the novel's first printing as a whole book, which occurred in 1897, after its serial run in McClure's was complete. If other copyright dates appear, they likely cover an abridgment of the text or a particular layout with a set of illustrations. Captains Courageous itself has long been out of copyright and in public domain, so it has been republished by many companies, which often gear their editions to younger audiences.
By the way, copyright data is listed on the reverse side of the title page in most books, although some older texts print the date on the title page itself, just below the publisher's name.