The First Civil War (1955-1972)

The Unequal distribution of power between northern and southern Sudan triggered the first civil war.

-The government promised Southern Sudanese to construct southern federal system.
-Southern Sudanese felt cheated and disenfranchised when the government did not keep the promise.
-The war began on August 18, 1955, when Equatoria Corps rebelled at Torit.

*Israel helped the rebels by shipping the weapons through Ethiopia and Uganda.

In 1972, Addis Ababa accords ended the war.

*Addis Ababa accords guaranteed southern Sudan's autonomy.

http://en.wikipedia.org/wiki/Addis_Ababa_Agreement_(1972)
http://www.globalsecurity.org/military/world/para/spla.htm