The main point of view of the "United We Win" poster from 1943 was that "<span>cooperation by all will result in American World War II victory", since it shows to people of different races working together for the war effort. </span>
I believe that they used the Oregon Trail
There were many factors that allowed the Byzantine Empire to last a 1000 years after the end of the Roman Empire which include the fact that Constantinople, the capital of the Byzantine Empire, was protected with walls that lasted almost the entire 1000 years, making Constantinople, and the center of the empire's economy/culture impervious to invaders.
Decennial census of population and housing.
