Today's link is a pay site. If you've ever made a period newspaper on photoshop from scratch, you know how much of a pain it is to make a good one. Trust me when I say, it is worth what ever you pay for a month long membership. Just make sure you take advantage of it and download as much as you can in that month. (This advice came from the APT props master, who happens to just get a membership when he needs it and downloads all he can.)
Anyway, you can search a ton of different newspapers from the US and select countries dating back to the 1700s. I wasn't the one to do the image pulling for the newspaper we made this year, so I haven't had really any interaction with the site. It seems easy enough to navigate. I'm pretty sure, much like the British Museum Archives, you get a decent amount of info as to the size of the paper and the number of pages each issue should be.
The best part is that the downloads come in PDF files of each page. So you can download single pages if you just need to create filler and mix and match different dates. For example, we used an Alabama paper called The Southern Immigrant for Another Part of the Forest. It's only a 4 page paper, but we needed an 8 page one, so 4 pages were pulled from other dates.
If possible, print the papers double sided on a large scale printer. SO much better than piecing together, even though loading is a pain. Granted, unless you happen to get newsprint big enough to do 2 pages on 1 sheet like a real paper, you'll have to tape together the 2 sides.
So there you go- NewspaperArchive.com. Check it out. You won't be able to take a good look unless you subscribe, but you can get a feel for the site by looking.