In part one, I mentioned the Library of Congress, The National Archives and DocsTeach. Let's look at a few other sites to use for primary source searching.
First of all, Historypin. History pin is Pinterest for primary sources. It features a series of projects loaded with images from all over the world. It's a global collection of materials that people don't normally see. There are projects, basically tagboards, loaded with images that relate. People add them to the community as a reference. When the board is opened, a map appears and community members pin an image, document, etc, to the map. It's a great idea, but it seems to be early in it's life cycle so it's continuing to grow. I would recommend this for Middle School age students and up. Some of the visuals may be difficult for a younger child to understand. (Holocaust, Genocide, etc.)
Second off, let's take a look at the Digital Public Library of America. This site is a huge collection of images, documents and artifacts that anyone can access free. Per their website: "The DPLA brings these different viewpoints, experiences, and collections together in a single platform and portal, providing open and coherent access to our society’s digitized cultural heritage." The site pulls information from libraries all over North America into one main location. It is loaded with things are it seems to be fairly easy to use. It has an exhibitions tab that focus on a specific topic. Within that exhibitions, users can see a large amount of information that pertains to a topic. It's a great way to get a lot of information.
Finally, the Life Magazine Photo Archive. Life Magazine's photo collection is by far one of the most vast photo collections out there with all sorts of images that can lead to writing prompts, research topics and even more. The page has been taken over by google, but the images are sorted by dates and as well as topics. They go back all the way to the 1860s.