Nigerian nationalism most serious threat to the Nigerian unity since Nigeria became independent in 1960, as other ethnic groups threatened that they too would also seek secession should Biafra successfully secede. Nigeria responded to the separatist threat with a military campaign against the Biafran government, resulting in the Nigerian Civil War from 1967 to 1970. The war ended with the defeat of the Biafran separatists. Between one and three million Nigerians died in the war. The 19th century did not witness the emergence of any political organization that could help in airing the grievances and expressing the aspirations of Nigerians on a
1967–1970 meanwhile, featured a clean version previously heard on the "" soundtrack album in 1988. The album liner notes state that all songs were produced by George Martin, except "Across the Universe" and "The Long and Winding Road" produced by Phil Spector, meaning that George Martin was credited as producer of the song "Don't Let Me Down" which usually has no official producer's credit. In the US, the album sold 1,294,896 double LPs by December 31, 1973 and 3,850,026 double LPs by the end of the decade. 1967–1970 1967–1970 (widely known as "The Blue Album") is a compilation of songs by