Colonisation affected people's freedom, and nationalist sentiments surged during the process of struggle against imperial domination. The sense of oppression and exploitation became a common bond for people from different walks of life, and this resulted in the growth of nationalist ideals. Thus, growth of nationalism in the colonies is linked to anti-colonial movements.

During the First World War, the British army conducted forced recruitment from rural areas in India. To finance the defence expenditure, high custom duties and income taxes were imposed. Also, during 1918-19 and 1920-21, crops failed in many parts of India, thereby resulting in acute food shortages. All this caused extensive anger and opposition against the British colonial rule, and the national movement of India headed towards a stronger, more definitive direction.

The Rowlatt Act was passed hurriedly through the Imperial Legislative Council despite opposition from Indian members. It gave the government autocratic powers to repress political activities besides allowing it to detain political prisoners without a trial, for two years. The Indian were outraged by this act as it was clearly undemocratic and oppressive, and hurt national sentiments and dignity.

Gandhiji decided to withdraw the Non-Cooperation Movement due to various incidents of violence perpetrated by the masses, especially the Chauri Chaura incident in 1922 where the people clashed with the police, setting a police-station on fire. Gandhiji felt that the people were not yet ready for a mass struggle, and that satyagrahis needed to be properly trained for non-violent demonstrations.

The different social groups that joined the Non-Cooperation Movement of 1921 were the urban middle class comprising lawyers, teachers and headmasters, students, peasants, tribals and workers. Peasants, tribals and workers joined the movement from the countryside. They did so with hopes of self-emancipation. Peasants rebelled against talukdars and landlords who demanded high rents and also forced them to do begar or free labour. Tribal peasants revolted against the enclosure of large forest tracts by the British government, which left them devoid of a livelihood as well as traditional rights. Plantation workers, on the other hand, desired freedom to move about and retain links with the villages they came from. All three believed that Gandhi Raj would come with the Non-Cooperation Movement, and this would mark an end to their sorrows. Hence, they joined the anti-colonial struggle.

The idea of satyagraha implies a unique method of mass agitation that emphasises the power of truth, and the need to search for truth. It upholds the belief that if the cause is true and the fight is against injustice, then there is no need for physical force or coercion against the oppressor. Satyagraha is synonymous with non-violent agitation, where an appeal is made to the oppressor's conscience to search for justice. Gandhiji believed that this dharma of non-violence could be the cause of national unity and harmony.

The Salt March was an effective symbol of resistance against colonialism because it was done in revolt against a commodity—salt, used by the rich and the poor alike. The tax on salt, and the government monopoly over its production was a severely oppressive administrative move. The Salt March was effective also because Gandhiji met a large number of commoners during the march and he taught them the true meaning of swaraj and non-violence. By peacefully defying a law and making salt against government orders, Gandhiji set forth an example to the whole nation of how the oppressor could be confronted in a non-violent manner. This also led to the Civil Disobedience Movement in 1930.

On 13th April 1919, a large crowd gathered in the enclosed ground of Jallianwala Bagh – some to protest against the British government’s repressive measures, others to attend the annual Baishakhi Fair. These people were unaware of the imposition of Marshal Law in the city. General Dyer, the Commander, blocked the exit points from the Bagh and opened fire upon the innocent citizens. Dyer’s intention was to produce a ‘moral effect’ and terrorize satyagrahis. Hundreds of innocent people including women and children were killed and wounded due to this indiscriminate firing by the British soldiers, which ultimately led to nation-wide outrage. Jallianwala Bagh incident was the most brutal incident in the History of India.