Surprising box-office hit (nearly $500 million worldwide!) is a zippy crowd-pleaser. Just don't expect historical accuracy. It's a light, frothy musical about how difference needs to be accepted and celebrated... um, by exhibiting those differences in circuses and carnivals and P.T. Barnum's weird-ass New York museum.
The movie is sort of set in the 1840's and 1850's, though this never seems to be stated and there are several elephant herds of anachronisms and mistakes to muddy the temporal waters. Let's just say that the real-world events the movie was "based on" occurred between 1840 and 1860 and that the movie itself in set in "the before-time" or perhaps "Oldey Timey Days." They're Oldey Timey because no one has a cellphone.
To understand the lack of historical accuracy, simply note that the depiction of P.T. Barnum in a recent episode of DC's Legends of Tomorrow was more accurate. And that's a goddam show about time-travelling superheroes.
Hugh Jackman, Zac Efron, a distracted-looking Michelle Williams and the rest of the cast sing and dance up a storm in what is essentially the world's longest United Colours of Benetton ad. To fully enjoy the movie, avoid finding out what travelling act first made P.T. Barnum famous. It's a racist show-stopper to movie enjoyment! Lightly recommended so long as no one mistakes it for history.