The Carnation Revolution in Lisbon, Portugal in 1974 established a military government that promptly ceased anti-independence fighting in Angola and agreed to hand over power to a coalition of three pro-independence Angolan movements. The coalition quickly broke down and the newly independent Angola broke into a state of civil war. Maintaining control over Luanda and the lucrative oil fields of the Atlantic coastline, Agostinho Neto, the leader of the MPLA, declared the independence of the Portuguese Overseas Province of Angolaas the People's Republic of Angola on November 11, 1975, in accordance with the Alvor Accords. UNITA declared Angolan independence as the Social Democratic Republic of Angola based in Huambo and the FNLA declared the Democratic Republic of Angola based in Ambriz. These differences reiginited civil war between UNITA and the MPLA. Agostinho Neto became the first president upon independence, and he was succeeded by José Eduardo dos Santos in 1979.
South Africa intervened militarily in favor of FNLA and UNITA, and Zaire and the United Statesalso heavily aided the two groups. Cuba deployed thousands of troops in 1975 to aid the MPLA against South African intervention, with the Soviet Union aiding both Cuba and the MPLA government during the war. In November 1980, the MPLA had all but pushed UNITA into the bush, and the South African forces withdrew. The United States Congress barred further U.S. military involvement in the country, fearing another Vietnam-style quagmire.
At its first congress, in 1977, the MPLA adopted Marxism-Leninism as the party ideology and added Partido do Trabalho (Labour Party) to its name.
After Nito Alves's attempted coup in 1977, Neto ordered the killing of suspected followers and sympathisers of "orthodox communism" inside and outside the party. Thousands of people were estimated to have been killed by Cuban and MPLA troops in the aftermath over a period that lasted up to two years, with some estimates claiming as high as 70,000 dead. After the violent internal conflict calledFractionism, it made it clear that it would follow the socialist, not the communist model. However, it maintained close ties with the Soviet Union and the Communist bloc, establishing socialist economic policies and a one-party state. Several thousand Cuban troops remained in the country to combat UNITA fighters and bolster the regime's security.
In 1990, when the cold war ended, MPLA abandoned its Marxist-Leninist ideology and on its third congress, in December, the party declared social democracy to be its official ideology.
The MPLA was victorious in Angola's 1992 general election, but eight opposition parties rejected the election as rigged. UNITA sent negotiators to the Luanda, where they were killed. As a consequence, hostilities erupted in the city, and immediately spread to other parts of the country. Tens of thousands of UNITA and FNLA sympathizers were subsequently killed nationwide by MPLA forces, in what is known as the Halloween Massacre, and the civil war resumed.] The war continued until 2002, when UNITA leader Jonas Savimbi was killed. The two parties promptly agreed to a ceasefire, and a plan was laid out for UNITA to demobilize and become a political party. Over 500,000 civilians were killed during the civil war. Human rights observers have accused the MPLA of "genocidal atrocities," "systematic extermination," "war crimes" and "crimes against humanity during the civil war." Rudolph Rummel, an analyst of political killings, estimated that between 100,000 and 200,000 Angolans died in the MPLA's democide between 1975 and 1987.