Just wanted to share one of my latest creations. It's a homemade page, so no printables available. I googled Samuel Morse for his portrait and then Morse code for the dots and dashes alphabet, copied them to a Word document, then printed.
I will have the kids draw and decorate the rest themselves. I pulled the most important information about the telegraph for the bite-sized pieces of information on this page. See image below for how to do the telegraph key (the button). Accordion fold a slip of scrap paper for the pushing action, cut out the key shape from an index card and tape into place. I hope your kids enjoy!