The cultural contributions of the <em>Byzantine Empire</em> were:
-Their great system of defense which consisted of 700 km of huge beacons that ran the border of the empire and kept them aware of possible invasions.
-One of the most beautiful and biggest church they built "Haidi Sophia".
-Very good hydraulic engineering techniques.
-They helped to preserve the Greek philosophy, ethics, culture, and language.
Hellenistic civilization included a blend of mainly Greek culture with Egyptian, Indian, and Persian influences.
The main factors were different ethnicities with different needs competing for territory and work. In places like Illinois, there was a huge rise in African-American migration from the south who started fighting with local Irish people who believed that African-Americans were taking their jobs. The problems in the employment and the housing markets caused them to clash against each other.