Thats a good question my dude
The correct answer is own land
In order to become a citizen in ancient Rome you had to be a man and own land. Women and slaves were not granted citizenship. Initially, only the people that lived within the city were considered as citizens
They used the Apalachian mountains. Hope this helped.
They were big headed because they thought they were the center of the earth...like everything was made around them when really they were just cut off from the rest of the earth