He founded a nationalist organization called the Indian National Association to bring Hindus and Muslims together for political action.

His ancestors had migrated to East Bengal at some point of time and settled in a village called Lonesingh in Faridpur district.

[2] After graduating from the University of Calcutta, he travelled to England in 1868, along with Romesh Chunder Dutt and Behari Lal Gupta, to compete in the Indian Civil Service examinations.

[13] In 1878 in a meeting to preach the Indian people he said 'The great doctrine of peace and goodwill between Hindus and Muslims, Christians and Paresees, aye between all sections of our country's progress.

[4] In 1883, when Banerjee was arrested for publishing remarks in his paper, in contempt of court, protests and hartals erupted across Bengal, and in Indian cities such as Agra, Faizabad, Amritsar, Lahore and Pune.

After the founding of the Indian National Congress in 1885 in Bombay, Banerjee merged his organization with it owing to their common objectives and memberships in 1886.

Banerjee was also one of the senior-most leaders of the moderate Congress — those who favoured accommodation and dialogue with the British — after the "extremists" – those who advocated revolution and political independence — led by Bal Gangadhar Tilak left the party in 1906.

[4] Banerjee was an important figure in the Swadeshi movement – advocating goods manufactured in India against foreign products — and his popularity at its apex made him, in words of admirers, the "uncrowned king" of Bengal.

Banerjee supported the Morley-Minto reforms 1909 – which were resented and ridiculed as insufficient and meaningless by the vast majority of the Indian public and nationalist politicians.

Banerjee could accept neither the extremist view of political action nor the noncooperation of Gandhi, then emerging as a major factor in the nationalist movement.

[4] He was elected to the reformed Legislative Council of Bengal in 1921, knighted in the same year[22] and held office as minister for local self-government from 1921 to 1924.

[4] His defeat at the polls in 1923 brought his political career to a close and he went on to write the widely acclaimed A Nation in Making, published in 1925.