Here are various Google (or Bing) searches that might help you uncover more primary source treasures for your elementary school students:
"primary sources" "elementary school" "history"
"primary sources" "elementary" "libguide"
"digital archives" "history" "elementary school"
Note - "libguide" is a type of software used by librarians to pull together or curate the best materials they can find on the web. When you search Google or Bing and include the word "libguide" you're crowdsourcing some pretty helpful folks!
