The concept that perhaps the southern States had the right to secede would not have been discussed. The Trail of Tears? The idea that the Louisiana Purchase had no validity because it wasn't French territory to sell? The Banana Wars? Lincoln as
There's lots of decisions in the last 240 years that don't stand up to a lot of scrutiny.
This is still the last best hope on the planet. Where else would you want to go?
Happy President's Day.