An Echo in the Bone by Diana Gabaldon
This is book 7 in the Outlander series. It takes us further into the American Revolution and gives us an up-close view of a few battles that took place between the American Army, such as it was, and the militia troops against the British Army and the Colonial Army (Americans for England).
I think Gabaldon does a great job with her historical research and I am still enjoying the story line of the Frasers and Mackenzies.
This book had a twist in that Brianna and Roger took their children back to the present. Really they went back to the 1980's but in the grand scheme of the book series that is the present. They were able to "keep in touch" with Brianna's parents through a stack of letters that were held for over a hundred years at the Bank of Edinburgh and then delivered to Roger's uncle the Reverend Wakefield. The good Reverend thoughtfully hung onto the box that had a metal plaque engraved with the name of Roger and Brianna's son.
When reading about time-travel, one must suspend all disbelief and just go with it and see where it leads. I really enjoy these books. There is a companion series that I am planning to start although I have a couple other books on my to read list first.