Why were bodies of water like the Mediterranean Sea important to civilizations like ancient Greece and ancient Rome? How are they important now?

They were important due to trade.

Explanation:

The kingdoms of old needed trade to function. Land routes were not safe, so sea routes were to go. Sea routes were also faster. They now are important as quicker ways to transport massive amounts of cargo. Have you ever seen a building sized cargo truck before? you get my point.

The ancient civilization of Greece was located in southeastern Europe along the coast of the Mediterranean Sea. The geography of the region helped to shape the government and culture of the Ancient Greek.In brief, the importance of the Mediterranean Sea is conditional and its nature favors continental control; it is a sea of passage and a sea of land powers. ... Thus, for Britain, the Mediterranean Sea was a key link to India as well as a means of influencing economic dynamics within continental Europe.

a

explanation:

a system of cooperative federalism emerged, as the powers of the federal government expanded.