That's one of the questions we received at the Reference Desk this week.
We thought others might be interested... So having read several articles and a few blog posts, we refer you to an article in The Telegraph. "How the King Found His Voice." Historian Andrew Roberts offers a decidely British slant on the film, but he does clarify what was exaggerated, which characters were not present at the speech in real life, and why Wallis Simpson was not depicted as positively as in American productions. The Telegraph offers links to several other articles on the topic, so if you're interested,