Ferris92 wrote:

Is it common for books written in English to have an American
edition and a British edition in which there are differences
in text besides the idiosyncrasies in spelling?

I don't know how far back the practice goes, or how universally it
applies, but I think it's fairly common. For example, Harry Potter and
the Philosopher's Stone became Harry Potter and the Sorcerer's Stone
when it was "translated" into American, and there were other differences
in the text, reflecting American usage.

I suppose there might sometimes be other changes than the strictly
"necessary" ones, either because the author sees a chance to edit
his/her work in preparation for an edition on the other side of the
Atlantic, or because such changes are made (or recommended/requested) by
the publisher's editors.

John