I just stumbled upon this cartoon short from 1935, Sunshine Makers. It's interesting; they make liquid sunshine out of sun light converted to electricity and then liquefied. Then they put it in milk bottles. The shadows of the characters just as the sunshine is going into the bottles is pretty amazing.
Then we see the other people - night people who are only happy when they're sad. A war breaks out. It reminded me of Walt Disney's Silly Symphony Music Land. They both kind of have the same premise, which is also strange because they were released the very same year!
But where Music Land ends in a beautiful merging of two kingdoms and two ideas, Sunshine Makers ends with one culture imposing its beliefs on another, against their will. It's actually a little hard to watch as a sunshine maker holds a night person down and forcefully pours the liquid sunshine down the night person's throat. The sunshine makers are so sure that their ways are right and the night people's ways are wrong they don't hesitate for a moment to bomb them and eradicate their way of life.
I know a lot of old cartoons are problematic but this one just struck me as especially relevant right now.