Anything I know about the brand... I know a lot, but not as much as the die-hard Elgin fans.
The brand was indeed located in USA, operated between 1864-1965 and made millions and millions of fine watch movements and watches.
It was one of the pioneers of large scale watchmaking (still it started off about 15 years later than Waltham), and it was one of the pioneers in the development of electric watches, but before their demise they did not release a successful design (only a flawed, unreliable one thay have to buy back from the buyers).
What I love... yes I love Elgin brand. I think it is among the most interesting and innovative large watch companies in the history of worldwide watchmaking.
By the way - the wristwatch shown in the film has the E logo and it comes from a post-Elgin period of Elgin brand, when the factory was long gone and Elgin brand watches were made elsewhere...