Religious and ethnic differences led to years of civil war, which resulted in South Sudan's independence.
Step-by-step explanation:
The first civil war between the North and the South broke out few months before the independence of Sudan on January, 1st, 1956 and was settled through peace. The second Sudanese civil war broke out on May, 16, 1983 and lasted until a peace deal was concluded in Naivasha, Kenya.
Insisting Arabism and Islamism were insisted by force on then south Sudanese which was not approved by the people who follow traditional African culture. The failure to manage diversity is what led to breakup of the Africa’s largest country.