To quote the Online Computer Library Center "Want to dig deeper? Explore a list of the top 500 novels held in WorldCat libraries to find more of your favourite genres and authors".
This is the 2nd part of the challenge and covers novels 251-500. Click on the link to go to the first part, which also has instructions about finding these books in libraries in your locality.
BTW, as an Aussie, I didn't stand a chance on this part, with so many books of an American childhood.