During the revolutionary war, which navy was larger france, or britain

Aside from low birthrates and high death rates, what can cause a country’s population to decline

In italy, the distance between milan in the north and palermo,sicily, in the south is about 550 miles. in the united states, the distance betweenboston, massachusetts, and savannah, georgia, is about 900 miles. do you think the american revolutionaries of 1776 in the 13 colonies faced some of the same challenges as the patriots who struggled for italian unity in the 1860s?  

How did the colonial army keep it self in the war during difficult year early years and what was the turning point of the war?