This is one of the reasons I like to do history stories. There are tons of images in the public domain. You also have to be careful with artwork, even it’s very old. The ancient Greek statue might not be copyrightable, but the photo of it sure can be.

Some art museums will claim that you can’t use images of the paintings they exhibit. That’s not necessarily the case. If the artist has been dead for 100 years, and the image is an exact reproduction, it can’t be copyrighted. The details are here. https://www.huffpost.com/entry/museum-paintings-copyright_b_1867076