The point is that under no measure is it true. If you go for nation as people’s identity, Japan, Egypt or China are millenia old. If by the current form of constitution then us constitution was amended in 1992 (IIRC). If we go by geographical borders, Hawaii and Alaska are 1960s additions. If we go by form of government, the UK is about a hundred years older. If we go by the base form of the constitution, ammendments be damned, either UK or San Marino are older.
And America will pay for it!