Scholars debate based on criteria:
Sumer (Mesopotamia, ~4th millennium BCE) — city-states (Ur, Uruk), writing (cuneiform), laws, temples, bureaucracy. Often called "cradle of civilization."
Egypt (~32nd century BCE) — unified kingdom under Narmer/Menes; 3,000+ years of continuous statehood, culture, language evolution.
"First country" is a modern construct applied to ancient polities. **Sumer** and **Egypt** are the two strongest candidates depending on definition.