OED Definition:
A religious and political movement founded in Detroit, Michigan, c1930 on precepts of black separatism and superiority and of Islam as the natural religion of African Americans.
The Nation of Islam is not considered part of mainstream Islamic orthodoxy, and as such should not be taken as representative of Islam or Muslims.
Founded by the elusive Wallace D. Fard, who was active in Detroit from 1930-34, the Nation of Islam proliferated under the leadership of his successor, Elijah Muhammad, who took over from Fard when the latter mysteriously disappeared in 1934. Though there is some borrowing of Islamic beliefs and practices, the Nation of Islam is strongly at variance with orthodox Islam. Elijah Muhammad, who taught his followers that Wallace D. Fard was God, combined the use of the Quran and the Bible to preach a “message of modern black prophecy that emphasized themes of the chosenness and salvific destiny of the ‘Blackman’…”
The Nation of Islam split after the death of Elijah Muhammad in 1975, with the followers of his son Warith Deen Muhammad converting to orthodox Sunni Islam. After the split, the original theology and eschatological beliefs of the Nation were carried on by Louis Farrakhan who remains active today.