The King of Elfland’s Daughter, a 1924 fantasy novel written by Lord Dunsany.
You might also like Lord Kalvan of Otherwhen by H. Beam Piper. Alternate universe not historical, but it’s about a modern day Pennsylvania State Police officer who gets thrown into a pseudo-medieval world where one kingdom has the monopoly on the miracle substance “fireseed”, something our hero recognizes as “gunpowder”…
You are all awesome … Thanks so much!
Rome, Sweet Rome, is kind of a weird, but neat one—a story about a modern Marine base swept back to the time of Augustus Caesar, inspired by a message board post, turned into an online short story, and sold as a Warner Bros. screenplay from there. 
Thanks again all and I think I’ll be giving all of these a read. Having a hard time finding tn he 1632 for kindle but I’ll get it … Thanks again
Sorry just found the free versions as suggested in this thread :-/
Seconded. Somewhat similar in tone is the Destroyermen series by Taylor Anderson… an American WWII destroyer ends up in an alternate world where the dominant life forms are dinosaurs and intelligent lemurs.
So you’re the third person to have read those books! Great series, and I’m glad he “tied it off and wrapped it up” rather than dragging it out over a never-ending 24-book series like a lot of fantasy series seem to do.
Maybe because he wrote them in the late 70’s (IIRC) and drag-out-forever series didn’t seem to start until Dragonlance came along in the mid-80’s.
It was a sad day Daley died. I would really have liked to have read what he came up with next. Or the futher adventures of Hobart and Alacrity, for that matter.
I wanted to take another moment to update this and thank you all … I’ve since read 1632 and am in the middle of the second book of the Axis in the sea of time series.
As some pointed out some of the things the ‘travelers’ did and didn’t do were kind of annoying but still it was a fun read.
One thing out of the Axis series I didn’t get was why didn’t the task force just …
take out Japan and Germany the minute they figured out what happened? Meaning why didn’t they nuke Hiroshima and Nagasaki quickly?
Anyway loving ALL these suggestions, about to run back into the Stirling stuff …
All this time and no one has mentioned ‘Guns of the South’? By Harry Turtledove?
Turtledove is uneven, God knows, but that one is a true classic. Racist time travelers travel back to 1864 and supply the Army of Northern Virginia with 100,000 AK-47s. It’s a brilliant book.
A good book worth reading. It’s sort of the opposite end of what the OP described. Instead of a bunch of people reacting to being thrown into the past and rewriting history, it’s a bunch of people reacting to having future travelers come back to their time to rewrite history.
yeah I just read a bit on the Jon and it does look interesting but as Little Nemo pointed out for some reason I’m still dorking out over people who are cast back in time without knowing why.
… still Guns of the South DOES look interesting and I’m sure I’ll get to it … thanks 
There is no main thread. The series is an expansion, not a line. Because of Flint’s personality, the series is a collection of dragging in any and every author he can find, each author having some element of the timeperiod they want to explore.
So far, I’m still interested. The Ring of Fire was more interesting than I thought it would be. I haven’t tried any of the Granville Gazette stuff, and probably won’t. TROF is a series of short stories, many of which set up characters and situations explored in the novels. Like the characters in TGA were introduced in TROF.
I loved those books. I bought a set. Then I lent them out, and they disappeared (the person moved away). So I bought replacements.
Loved those! Especially the fight with the dragon…
Couldn’t get into the Italian thread (and I admit the doper semi-main character is part of the reason), but I’m really enjoying the 1632/1633/Baltic War/Bavarian Crisis line, and am looking forward to continuing it with The Eastern Front, The Saxon Uprising and A Parcel of Rogues. Looking forward to the American thread, too…
The Saxon Uprising and The Kremlin Games are both pretty good. The American thread could be good, but what I’m waiting for is seeing Julie take on Charles I.
“Household Gods” by Harry Turtledove and Judith Tarr. It’s a much more intimate and smaller scale story than many of the others listed, just single woman thrown back in time to the 2nd century AD.
An astoundingly ignorant woman…
Now, now, that’s not fair…merely saying “astoundingly ignorant” could lead to false assumptions about the woman’s character. After all, it’s possible to be astoundingly ignorant WITHOUT being an unpleasant, harsh, histrionic, chillingly self-absorbed harridan; and we shouldn’t wish any potential readers assume the same in this case.
Turtledove did well with the setting, though.