My family has had a pretty high correlation of watching historical movies and reading the related books, especially this year.
We saw Hidden Firgures in 2016, but did not end up reading Margot Lee Shetterly's book until this year.
Also this year we watched A United Kingdom and read both Colour Bar: The Triumph of Seretse Khama and His Nation by Susan Williams and A Marriage of Inconvenience: The Persecution of Ruth & Seretse Khama by Michael Dutfied. (There is also a related TV movie from 1990, but we haven't seen that.)
When we saw A United Kingdom there was a preview for The Zookeeper's Wife, which we thought looked interesting. We later saw that and read the book of the same name by Diane Ackerman.
(We also went to see Dunkirk this year, but we haven't read anything on it, and we read Unbroken by Lauren Hillenbrand this year, but we haven't seen the movie.)
I have done some additional reading on some of them, via articles or researching specific issues. We always wonder about things, but I suppose the base question is always about the accuracy of the movie: how true to life was it?
I'm not saying that this is a general rule for all movies, but most of the movies listed did pretty well. The main issue seems to be condensation. Spoilers will follow.
There is compression of time. When Baby Jacqueline is born and the Khamas take her to England, it is several years before they go back for that meeting with her father's uncle. Of course, more babies had been born too, so perhaps that is also compression of characters.
For example, there really was a Nazi zoologist, Lutz Heck, who took some of the animals from the Warsaw zoo, wanted to breed back older species, and had a crush on Antonina Zabinska. There was a soldier who took her son out of sight and fired a gun, terrifying her but ultimately not killing Ryszard. They were not the same people.
That is understandable, in a way. There should be higher emotional stakes in having the threat come from someone who has loomed so large in the story, though you could argue that the emotional stakes of fearing for your son's life are already pretty high. It is realistic to have fear about what any Nazi will do.
Beyond that, there were three other Heck's, the father and brother of Lutz. You learn about all of them in the book, but in the movie you don't really need them, nor more characters to track.
Sometimes these things are easy to guess. After watching Hidden Figures, I suspected (correctly) that Katharine Johnson, Dorothy Vaughn, and Mary Jackson were probably not really best friends. They had friends, and those friendships were important, but there were a lot of women working at NASA over many years, making it less likely that the three most prominent (the book discusses a fourth, Christine Darden) were also in the same carpool.
I had two other good guesses from there, being that Katharine Johnson never really got to have a rant like in the film (she would have deserved it, but Black women are still rarely allowed that), and also that the issues were not really resolved by heroic Kevin Costner ripping down the signs segregating the bathrooms. That seemed unlikely, especially because his character did not seem to have on single correlating historical figure. However, if you put Kevin Costner in your movie you have to give him something important to do. Everybody knows that.
The real story is more complicated, with things like one women removing the label segregating the coffee every day until they gave up replacing it. Her friends told her she was going to get fired, but she prevailed. Practical persistence gets results more often than dramatic moments.
Maybe that's the most important thing to remember. As much as we want things resolved quickly and definitively, history tells us that is much less likely than movies would have us believe. That may sound like a reason for discouragement, but it is really a reason for persistence, and endurance.
Some of the books mentioned will be treated in other posts that I will get to eventually, but first I am going to spend some time on some actors and Hollywood, and that can be very discouraging.