Historical inaccuracies

This is a decent enough movie with an interesting story, but it's hard not to chuckle at a few a of the historical flaws. Most notably, the story takes place after the Spanish-American war (1898) but the world they travel though seems more like the post Civil War (1865) wild west. The Chinese coolies building the railroad, dangerous "Sioux territory", and rampant KKK attacks all describe an America a few decades younger. Jesse makes reference to the "Dakota Territories" when North and South Dakota were already states for over decade. The American flag displayed in town is a modern 50 star flag that wouldn't have been seen for half a century.