1632, by Eric Flint

I first read this last year, and thoroughly enjoyed it. My previous
review
explains the book tolerably well, so I won’t go into all that
here. The short version is this: for a thoroughly and comprehensively
and artistically absurd reason, the town of Grantville and
its environs are transported from modern day West Virginia to the Germany
of 1632. The 30 Years War, a truly nasty conflict, has been on-going for
about fifteen years; mercenary troops loot, pillage, and rape freely.
The citizens of Grantville conclude almost unanimously that This Has Got
To Stop, and proceed to open the biggest can of whup-ass that Thuringia
has ever seen.

The whole thing is unlikely, of course; still, it’s a delight to read a
book that celebrates American values and recognizes that there are ideals
worth laying down our lives for.