The question you asked might need to be fleshed out some more but in essence if you are using a photo of a public location taken by you or someone you hired to take that picture (work for hire is the term in copyright law) and you own the copyright, that might be permissible but you would need to ensure that particular items in the photo do not in and of themselves have a copyright that limits your use.  This is probably highly unlikely if on a public site (think public location).  The name of a historic site needs to be checked to ensure it is not trademarked or copyrighted before you use it on a product line.  Of course, you may wish to inquire with the federal government's agency or agencies concerning the oversight of such historic sites. The last thing you want is to invest in the creation of the products only to receive a cease and desist letter.