Answer:
Population growth and diversity.
Explanation:
In an area with multiple enthic groups and people, socilization and growth leads to others exploring new cultures and learning about them and sharing them. This could also lead to new cultures being forged from two original cultures.
Wyoming,Utah,Colorado,Idaho,Washington
Indochina, Only Indochina really repelled the Mongols.
The current president of the USA is Barack Obama. He is a member of the Democratic Party and is the first African American to ever be elected to the presidency.