Fair Use Doctrine

I am displaying articles from old newspapers on my website using the "fair use" doctrine of the Copyright Act, basing this on four points:

1. My website is for nonprofit, educational purposes.
2. All newspaper articles, and the newspapers they came from, are long out of print.
3. For any day, one newspaper article is a minor part of the whole newspaper.
4. The potential market for, or value of the newspaper article, is negligent.

I could have just as easily summarized the article, but I think that seeing it is more interesting.