Jillaine, I'm responding to the comment below, but also the original question, "Have you uploaded a copyrighted image?" Perhaps it shoud be retitled "Have you uploaded a scan from a copyrighted book"? They are different questions with different answers.
Providing open access to a digitized photograph even if you don't own the copyright does not violate U.S. law; context and intent matter. If the context is for "teaching, scholarship, and research" and "nonprofit education purposes" we are within our rights to share them. Selling reprints or access to them would not be legal.
Here's an example based on a typical scenario.
A local historical society (or university/library/archive/musem) has a collection of photos important to the history of their town and its residents. Nobody knows who took these photos; they are either of "uknown provenance" or the copyright holder cannot be located. Digitizing those photos and making them available for the public is legal and within their rights so long as the project is free and open access (i.e. not sold to a database company) and there is no financial or personal harm done to the copyright holder (i.e. s/he's losing money because of this).
Non-profit is the key to Fair Use for photographs. If that same historical society started selling reproduction rights to their collection or if an author reprinted them in a book that was sold, then we are outside of Fair Use. For the most part, it comes down to money.
Print is a different story. No, you can't legally share that scan from TGM on the Internet; it's still for sale and it makes its publisher money. Please note that copyright law is evolving regarding print (see the ongoing Google Books case over orphan works).
Photos make history alive for a highly visual culture. Let's be careful not to discourage people from sharing photos on Wikitree over an irrational fear of a lawsuit or hurting the creator's rights. Thank you for reading.
