Why does the author include information about
how difficult life was in ancient Greece?

Navigation Acts, in English history, a series of laws designed to restrict England’s carrying trade to English ships, effective chiefly in the 17th and 18th centuries. The measures, originally to encourage development of English shipping, became a form of trade protectionism during an era of mercantilism.

Explanation:

Middle Passage, the forced voyage of enslaved Africans across the Atlantic Ocean to the New World. It was one leg of the triangular trade route that took goods from Europe to Africa, Africans to work as slaves in the Americas and the West Indies, and items produced on the plantations back to Europe.