By using a concept born in 1915
It was 'The Great Migration.'
"The Great Migration<span> was the movement of 6 million African-Americans out of the rural Southern United States to the urban Northeast, Midwest, and West that occurred between 1910 and 1970."</span>
1. Energy shortage, high inflation, and high unemployment.
2. Worldwide oil shortage
Sorry but I’m not sure what 3 is.
The answer to this question is a government
The correct answer is "Have a common language and religion".
They speak a language whose origin is unknown and are now mostly catholic, even though they had their own religion a long time ago.