These books take place "a while" ago. Mostly they give a good sense of place and time, and a child can learn a lot from them if she isn't paying attention.
The "Shoes" books by Noel Streatfeild:England from the 1930s to the 50s---from the depression, through WWII, and afterwards recovering from bombings and dealing with rations. Plus, stories about being on the stage and performing, which I have no personal experience with. My favorite is "Skating Shoes" or "White Boots," which is not available in the US (except by amazon.co.uk)...
Little House on the Prairie by Laura Ingalls Wilder: Whenever I feel like my life is difficult, I reread "The Long Winter." At least I'm not grinding wheat in a coffee mill to make bread for my only meal of the day. I also really like "Farmer Boy." There are new books coming out about Laura's daughter, mother, grandmother and great-grandmother. They are pleasant to read, but not great, in my opinion.
Anne of Green Gables by L. M. Montgomery: I was only able to read the first two when I was younger, after that there was too much "love stuff" and not enough adventure. I love them now, though.
The Wouldbegoods and The Railway Children by E. Nesbit: These are two of her non-magical books. The Wouldbegoods especially made me laugh out loud. Michael likes the magical books, I don't as much.
The Four-Story Mistake by Elizabeth Enright: This takes place in America earlier in this century. I found the children interesting, especially their huge intricate projects. There are other books about the Melendy children, but I haven't read them recently.
The Black Rose by Thomas B. Costain: 1200s England to China and back. Just thinking about the founding of Oxford (where the first scene takes place) is fun.
Kidnapped (and Treasure Island) by Stevenson: I much prefer Kidnapped. There is a lot going on, although it helps if you already have some idea of what is happening politically before you start. The Black Arrow is amusing, but not so gripping.
The Great Brain by Fitzgerald: A Catholic boy growing up in Utah in the late 1800s. I loved getting the picture of the west at that time. Everything I learned about Catholicism as a child I learned from these books.
This list wouldn't be complete without pointing out that Eleanor really likes The Magic Treehouse series and The American Girls series. I will say that they aren't as bad as they could be for amazingly popular, over marketed books.
Michael likes Swallows and Amazons by Arthur Ransome.
I'd better stop, there are hundreds more. For instance, Rosemary Sutcliff and Britain before and during the Roman occupation, The Bronze Bow by Elizabeth Speare, Johnny Tremain, Betsy Tacy and Tib, etc. The above list contains the books that I remember without looking at my bookshelves. Are there any that you especially love?
next up: the fantasy/science fiction/magic lists.