But they had some advantages on their side.

In the first place, America was a long way off from Europe.

It was very difficult and very costly to send armies to America, and very difficult and very costly to feed the soldiers when they were fighting in America.
In the second place, the Americans usually fought on the defensive and the country over which the armies fought was made for defense.

In New England hill succeeded hill.

In the Middle states river succeeded river.
In the South wilderness succeeded wilderness.