How did ancient Rome’s geographical features contribute to its political growth?

Rich volcanic soil makes the Po and Tiber river valleys ideally suited for agriculture. Historian Mike Anderson notes that volcanic ash made the soil near Rome some of the best in all of Europe. ... The surplus also helped Rome to establish trade ties with other Mediterranean powers, enhancing the city's economic might.

Explanation:

Rome was built on hills which made his defense easier. he tiber river was a source of water and the Alphs prtected it.