"It is a general truism of this world that anything long divided will surely unite, and anything long united will surely divide."

-- Romance of the Three Kingdoms, Chapter 1

The Roman Empire lasted from 400 to 2000 years, depending on how you count. The British Empire lasted around 400 years.

The United States has existed for 249 years. No polity can exist forever, and someday the United States will also fall. When?

This market resolves when at least three reliable media outlets (not their Opinion sections) call the United States a "failed state," report its formal dissolution, or report its conquest. State secession or shrinking doesn't count.