When sailors from England came to Roanoke Island in 1590, they found that the colonists left there two years before had

Gold and Silver

Explanation:

i Searched it up and it said ”The Roanoke Colonies. The Roanoke Colonies were an ambitious attempt by England's Sir Walter Raleigh to establish a permanent North American settlement with the purpose of harassing Spanish shipping, mining for gold and silver, discovering a passage to the Pacific Ocean, and Christianizing the Indians”

to replace ineffective because   andrew jackson's spoil system was a deliberate policy after he became president to remove federal employees he considered to be political opponents and replace them with his own supporters.