The Congress was founded by Indian and British members of the Theosophical Society movement, most notably A.O. Hume. It has been suggested that the idea was originally conceived in a private meeting of seventeen men after a Theosophical Convention held at Madras in December 1884. Hume took the initiative, and it was in March 1885 that the first notice was issued convening the first Indian રાષ્ટ્રીય Union to meet at Poona the following December.

Founded in 1885 claiming that it had the objective of obtaining a greater share in government for educated Indians, the ભારતીય રાષ્ટ્રીય કોંગ્રેસ was initially not opposed to British rule. The Congress met once a year during December. Indeed, it was a Scotsman, Allan Octavian Hume, who brought about its first meeting in Bombay, with the approval of Lord Dufferin, the then-Viceroy. Womesh Chandra Bonnerjee was the first President of the INC. The first meeting was scheduled to be held in Pune, but due to a plague outbreak there, the meeting was later shifted to Bombay. The first session of the INC was held from 28–31 December 1885, and was attended by 72 delegates.

Within a few years, the demands of the INC became more radical in the face of constant opposition from the government, and the party decided to advocate in favour of the independence movement, as it would allow for a new political system in which they could be a majorly dominant party. By 1907 the party was split into two halves—the "Garam Dal" (literally "hot faction") of Bal Gangadhar Tilak, or Extremists, and the "Naram Dal" (literally "soft faction") of Gopal Krishna Gokhale, or Moderates—distinguished by their attitude towards the British colonists. Under the influence of Tilak, the Congress became the first organised independence group in the country, bringing together millions of people against the British.

In the pre-independence era, the INC featured a number of prominent political figures: Dadabhai Naoroji, a member of the sister Indian National Association, elected president of the Congress in 1886, and between 1892 and 1895 the first Indian Member of Parliament in the British House of Commons; Bal Gangadhar Tilak; Bipin Chandra Pal; Lala Lajpat Rai; Gopal Krishna Gokhale; and Mohammed Ali Jinnah, later leader of the Muslim League and instrumental in the creation of Pakistan. The Congress was transformed into a mass movement by Surendranath Banerjea and Sir Henry Cotton during the partition of Bengal in 1905 and the resultant Swadeshi movement. Mohandas Gandhi returned from South Africa in 1915 and with the help of the moderate group led by Ghokhale became president of the Congress and formed an alliance with the Khilafat movement. In protest a number of leaders—Chittaranjan Das, Annie Besant, Motilal Nehru—resigned from the Congress to set up the Swaraj Party. The Khilafat movement collapsed and the Congress was split.

મહાત્મા ગાંધીની લોકપ્રિયતામાં વધારા સાથે અને તેમની પરિવર્તન ની સત્યાગ્રહ કળા થી સરદાર વલ્લભભાઈ પટેલ, પંડિત જવાહરલાલ નેહરુ (રાષ્ટ્રના પ્રથમ વડાપ્રધાન), ડૉ. રાજેન્દ્ર પ્રસાદ (રાષ્ટ્રના પ્રથમ પ્રમુખ), ખાન મોહમ્મદ અબ્બાસ ખાન, ખાન અબ્દુલ ગફાર ખાન, ચક્રવર્તી રાજગોપાલાચારી, ડૉ. અનુગ્રહ નારાયણ સિન્હા, જયપ્રકાશ નારાયણ, જીવતરામ ક્રિપલાની અનેમૌલાના અબ્દુલ કલામ આઝાદ આવ્યા. With the already existing nationalistic feeling combined with Gandhi's popularity, the Congress became a forceful and dominant group of people in the country, bringing together millions of people by specifically working against caste differences, untouchability, poverty, and religious and ethnic boundaries. Although predominantly Hindu, it had members from just about every religion, ethnic group, economic class and linguistic group. In 1939, Subhas Chandra Bose, the elected president in both 1938 and 1939 was expelled from the Congress for his socialist views and the Congress was reduced to a pro-business group financed by the business houses of Birla and Bajaj. At the time of the Quit India movement, the Congress was undoubtedly the strongest revolutionary group in India, but the Congress disassociated itself from the Quit India movement within a few days. The ભારતીય રાષ્ટ્રીય કોંગ્રેસ could not claim to be the sole representative of the Indian people as other parties were there as well notably the Hindu Mahasabha, Azad Hind Sarkar, and Forward Bloc.

The 1929 Lahore session under the presidency of Jawaharlal Nehru holds special significance as in this session "Poorna Swaraj" (complete independence) was declared as the goal of the INC. 26 January 1930 was declared as "Poorna Swaraj Diwas", Independence Day, although the British would remain in India for 17 more years. To commemorate this date the Constitution of India was formally adopted on 26 January 1950, even though it had been passed on 26 November 1949. However, in 1929, Srinivas Iyenger was expelled from the Congress for demanding full independence, not just home rule as demanded by Gandhi.

After the First World War the party became associated with Mohandas K. Gandhi, who remained its unofficial, spiritual leader and mass icon even as younger men and women became party president. The party was in many ways an umbrella organization, sheltering within itself radical socialists, traditionalists and even Hindu and Muslim conservatives, but all the socialist groupings (including the Congress Socialist Party, Krishak Praja Party, and Swarajya Party members) were expelled by Gandhi along with Subhas Chandra Bose in 1939. Members of the Congress initially supported the sailors who led the Royal Indian Navy Mutiny. However they withdrew support at the critical juncture, when the mutiny failed. During the INA trials of 1946, the Congress helped to form the INA Defence Committee, which forcefully defended the case of the soldiers of the Azad Hind government. The committee declared the formation of the Congress' defence team for the INA and included famous lawyers of the time, including Bhulabhai Desai, Asaf Ali, and Jawaharlal Nehru.

Pro Islamic Bias
આઝાદી પહેલાનો યુગ
The post-independence era
Controversies and criticisms