Which principle of the u. s. constitution is reflected in this passage

Assuming that this is referring to the same passage that was posted before with this question, the correct response would be the "separation of powers", since it talks about checks and balances within the government. 

Contributing factors  leading  to the harlem renaissance were the great migration of african americans to northern cities, which concentratedambitious  people in places where they could encourage each  other, and the first world war, which had created new industrial work opportunities for tens of thousands of people.