Transcript
A threads post saying "There has never been another nation ever that has existed much beyond 250 years. Not a single one. America's 250th year is 2025. The next 4 years are gonna be pretty interesting considering everything that's already been said." It has a reply saying "My local pub is older than your country".
The US civil war didn't overhaul the entire system of government though, like what happened to Japan after WWII
I would say the 13th, 14th and 15th amendment, the Civil Rights Act of 1875, the various enforcement acts in the early 1870s, etc. did overhaul the system of government, by changing what it meant to be a citizen, defining people's rights more explicitly, and outlawing slavery. Given that black people made up about 20% of the population, suddenly (theoretically) allowing them to vote and giving them the rights that non-slaves had was a pretty major change.