A little history-writing move to try: after a student uses a piece of evidence, ask, ‘What does that help you show?’ Have them explain it out loud, then put that explanation into the paragraph.
If the explanation just repeats the fact, there's still some thinking to do. What is the claim? How does this particular detail support it? Students can trade paragraphs and underline the sentence where that connection actually happens. If neither partner can find it, they have a useful place to start revising.
I've put a worked example and a short practice into a free one-page AP History handout. The example is World History, but the same check works with U.S. History evidence. No signup or purchase needed:
https://cllearninglabs.com/resources/ap-history-facts-to-argument
I'm Mark, a former history teacher and the founder of CL Learning Labs. This is a resource from my company, and the PDF includes a brief mention and link to Coach for AP World History, our separate paid product. The handout stands on its own and can be used without Coach.
How do you help students tell the difference between giving evidence and explaining what it shows?