It could also be a US film that focuses on Remembrance America in some way to make it more analogous to Birth of a Nation. Perhaps it tells the story of John Brown and how right he and his sons were to fight the South before the War of Secession because they knew how bad it was ?Another thing, One of the first ever blockbusters, Birth of the Nation from 1915 (One which has aged horribly) focuses heavily on Reconstruction. So this really makes me wonder what the first Blockbuster in TL 191 would be about. Seeing that the Union and Confederacy would be at war in 1915, I can see it being a Confederate Propaganda Film that focuses on the South's glorious victories in both the Mexican War and War of Secession. It could even still maintain it's name "Birth of a Nation."