Introduction:
The non-cooperation movement was started by Mahatma Gandhi in 1920 as a peaceful protest against the oppressive policies of the British government in India. The movement aimed to unite the Indian people in a non-violent struggle for independence from British rule.

Reasons for starting the non-cooperation movement:
1. The British government had introduced a series of policies that were detrimental to the interests of the Indian people, such as the Rowlatt Act, which allowed the government to imprison people without trial and curtail their civil liberties.
2. The British government had also suppressed the Khilafat movement, which was a movement by Indian Muslims to support the Caliphate in Turkey.
3. The Indian National Congress, which was the main political party in India at the time, had failed to achieve any meaningful concessions from the British government through peaceful means.

The non-cooperation movement:
1. The non-cooperation movement called on Indians to boycott British goods, institutions, and services.
2. It also urged Indians to withdraw from any government institutions, such as schools and courts, that were controlled by the British.
3. The movement was largely peaceful, with protesters using non-violent means such as strikes, protests, and civil disobedience to make their voices heard.

Why Gandhi called off the movement in 1922:
1. The Chauri Chaura incident: In February 1922, a group of protesters in the town of Chauri Chaura in Uttar Pradesh killed 22 police officers. Gandhi believed that violence had no place in the non-cooperation movement and called off the movement as a result.
2. Pressure from other Congress leaders: Some Congress leaders believed that the movement was causing more harm than good to the Indian people, and that it was time to adopt a more moderate approach to achieving independence.
3. The failure of the movement to achieve its objectives: The non-cooperation movement failed to achieve any meaningful concessions from the British government, and many Indians were left disillusioned by the lack of progress. Gandhi believed that it was time to reassess the approach to achieving independence.

Conclusion:
The non-cooperation movement was an important milestone in the Indian independence movement, and it paved the way for future non-violent protests and civil disobedience campaigns. Although the movement was called off in 1922, it had a lasting impact on the Indian people and their struggle for independence.