The Non-Cooperation Movement was led by Mahatma Gandhi starting in 1920 in response to growing British oppression in India including the Rowlatt Act, Jalianwala Bagh massacre, and Indian soldiers dying in World War I while Britain exploited Indian wealth. The movement aimed to resist British rule through non-violence and was supported by the Indian National Congress. It lasted from 1920 to 1922 but was called off when a violent clash broke out in Chauri Chaura, leading Gandhi to fast and urge Indians to stop resisting. The movement boosted Indian industries, reduced foreign imports, and promoted khadi while ruining some British-backed industries.