Throughout history, why were gold and silver the preferred kinds of commodity money?

They are valued metals unlike the paper bills today which is given the value in the hands of the government and are just printed. Gold and silver also have all the main components that money should have, portability, limited supply, durability, divisibility, uniformity, and so on. 

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.