Good Time! I can help you answer the question.
1. Large size;
2. Obtaining land by war with Mexico;
3. Stealing land from the Indians;
4. Colonialism in the Pacific and the seizure of the Hawaiian Islands;
5. America decides to imitate European empires;
6. The first world war shattered Europe, but not USA;
7. World war II devastated Europe and Asia;
8. Collapse suffered European colonialism but not USA;
9. The division of the world in the cold war;
10. Europe has joined us in NATO;
11. America spends more on defense than the next 12 countries combined;
12. America has the advantage in science, democracy and freedom of creativity, and it attracts immigrants;
This is the most basic facts!