How do I find an ISBN number for an outdated book?

I am wanting to sell a book series, "Abraham Lincoln" by Carl Sandburg. It is like the second edition from I think the 1950's. They must not have had ISBN numbers back then. I am unable to sell the series on half. com without the number. Any ideas how to find or create such a number?|||try this website :-


http://www.biblio.com/





I entered those details and it returns a Seller Inventory number which may be a substitute for the newer ISBN.|||published September 28th 2005 by Galahad


binding Hardcover, 776 pages


literary awards Pulitzer Prize for History (1940)


isbn 0883658321 (isbn13: 9780883658321)





or


published November 1st 2007 (first published 2005) by Sterling


binding Hardcover, 464 pages


literary awards Pulitzer Prize for History (1940)


isbn 1402742886 (isbn13: 9781402742880)