I loved the American Girl books, too! I especially remember the Samantha books and the Kaya books, and Addy.

If (for whatever reason) you're ever looking for a rec list of the best Dear America books, hit me up because a bunch of them still hold up pretty dang well! Also, you might have already heard of this one, but a really good middle-grade book about the Revolutionary War is Chains by Laurie Halse Anderson (I was going to say it was published recently-ish until I went to double-check and saw it came out in 2010...)