Can someone give me some point as how rome and usa are similiar and how they're different?

alike- (read) Dominant powers: “Rome and America are the most powerful actors in their world, by many orders of magnitude. Their power includes both military might and the ‘soft power’ of language, culture, commerce, technology, and ideas

different- (read) Government: “Rome emerged out of a city-state and took centuries to let go of a city-state’s method of governance; America from early on began to administer itself as a continental power