Copyright, strictly speaking means the right to copy. And there are restrictions – predominantly to give credit for and financial compensate to those who created a body of work.
This includes photos whether digitally available or in print format.
Just because you own a physical copy of something (a print, a photo, a book), it does not mean you can re-produce it.
Rather than go into a subject that is complex and fraught with potential liability, and for which I am not qualified I urge you to check with each website or archive from which you have gotten a photo or piece of artwork to find out about copyright restrictions and permissions of things in their collection.
Here is is the Canadian government’s guide to copyright
And here is a small business organization’s site that seems to do a good job of explaining copyright from a Canadian perspective.