All of the following are improvements that King Darius made to the Persian empire EXCEPT: Built good roads connecting the empire.
Implemented a uniform system of weights and measures.
Created a government system that was centrally controlled.
Adopted the same coin money throughout the empire.

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.