However, determining whether certain photos are in the "public domain" is not as straightforward as you might think. It depends when the photo was originally published, where it was published and whether the copyright holders properly renewed the copyright rights when the terms came up for renewal.
It is possible that the magazines may still be entitled to the copyright rights on the photos, in which case you would need permission from the magazine to use them. Best to speak to an intellectual property to map out your strategy for using them.
Nina L. Kaufman, Esq. is an award-winning New York City attorney, edutainer and author. Under her Ask The Business Lawyer brand, she reaches thousands of entrepreneurs and small business owners with her legal services, professional speaking, information products, and LexAppeal weekly ezine. She also writes the Making It Legal blog.