The Assam agitation began in 1979, led by All Assam Students Union and All Assam Gana Sangram Parishad, to compel the government to identify and expel illegal immigrants and prevent new immigration. The agitations were normally peaceful, with stray incidents of violence. The movement ended in 1985 with the Assam Accord that was signed by the agitating leaders and the Government of India. The agitating leaders then formed a political party Asom Gana Parishad (AGP) which came to power in Assam in the Assembly elections of 1985.
Migration into Assam began when the British developed the tea industry in Assam and imported labourers from Bihar because the Assamese people, living mostly in Upper Assam, were not interested in working as labourers in the tea gardens. Bengali Muslim peasants from present day Bangladesh were encouraged to move into lower Assam to cultivate virgin land to meet the food requirements for the tea labourers. This movement started developing both communal and political overtones over time.
When Bengal was partitioned in 1905, Assam was merged with the new Muslim majority province of East Bengal. This led to popular resentment The Assamese feared loosing their identity. This fear was aroused by the large numbers of Bengali Hindus dominating the administration, and the Bengali Muslims altering the demography of the province. The Assamese were concerned that they would be reduced to a minority in their home state, losing political control as well as employment opportunities.
After partition in 1947, despite an international border separating Assam and East Pakistan, immigration continued. Ethnic, linguistic and religious commonality between the illegal migrants and the people on this side of the border facilitated infiltration, and made their detection difficulty. Some political parties also encouraged illegal migration in order to build vote banks.
The Assam Accord defined illegal migrants as those who had infiltrated illegally after 24 December 1971. However, those who had infiltrated illegally between 1 January 1966 and 24 December 1971 were to be given Indian citizenship after a lapse of ten years.
In 1983, the government of India forced an election in Assam, despite a defective voters list. The plea was that there was not enough time to revise the electoral rolls before the election. There was widespread violence during this agitation including the infamous massacre of 1,700 Bengali Muslims at Nellie by the Lalung tribe.
After years of agitation and several demands for the detection and deportation of foreigners, the agitators reached a settlement with the Government of India in 1985. Beside other issues agreed on, the Assam Accord stipulated fencing of the border with Bangladesh to prevent illegal immigration. This was quite futile as Assam shares a 262 km border with Bangladesh of which 92 km is riverine.
The rise of Islamic fundamentalist groups has caused grave concern. Besides the threat of being relegated to minority status, rapid escalation of unemployment and the insularity of the Center have aggravated the situation. Disaffected Bodo tribesmen began agitating for an autonomous state. Throughout the 1990s and into the 21st century, the militant United Liberation Front of Assam (ULFA) has waged a vigorous guerrilla campaign for the outright secession of Assam from India. As of now, the situation is under control with more and more leaders joining the mainstream.