I received this resource from an online virtual conference and thought you might enjoy, if you're not already familiar with it. Here is a PowerPoint from the Library of Congress about Free Primary Sources and Strategies for teaching with them including a photography analysis. Here is a link to their Primary Resources sets:
And here are other resources for teachers from the Library of Congress:
If you see something that interests you, please let me, April, Kristi and/or Terry know; we'd love to work with you on something!