If you ever get a chance to travel back in time, don't forget to bring a good camera. Many people would be amazed at how much historical societies charge for scans of old photos from the 19th Century the rights to which are owned by nobody. But that's not all--you need to pay another fee per image in order to be able to use it commercially--once. I know historical societies need funds to operate but most writers are not wealthy and can end up forking over several hundreds of dollars to illustrate a book not very profusely.
Then there are old letters. These are invaluable for their historic content but most of the institutions that house them seem to believe they own them and demand permission to reproduce them or publish any of their content. A fee for photocopying and mailing is understandable but these places need to learn the concept of "public domain". Having something in ones possession does not mean owning the copyright. Every letter or even email an individual writes is his or her intellectual property and an automatic copyright is attached to it for as long as the law allows. The recipient or keeper of the communication has no rights--cannot reproduce it, publish it without permission of the author. Until such day as the communication outlasts its copyright. There is no letter written, say, in the mid-19th Century that is not in the public domain. One institution with which I recently dealt forced one to sign an online agreement while ordering a copy of old letters in its archives. In other words, if they are so clueless as to sue you for copyright volations regarding these antique papers and they lose, they are still held harmless for your attorney fees under the agreement! And this is a religious organization. Pretty sad.