The Gandhi cap is a white coloured sidecap, pointed in front and back and having a wide band. It is made out of khadi. It takes its name after the Indian leader Mahatma Gandhi, who first popularised its use during the Indian independence movement. Worn commonly by Indian independence activists, it became a symbolic tradition for politicians and political activists to wear it in independent India.

The Gandhi cap emerged in India during the First Non-cooperation movement during 1918-1921. When it became the standard Congress dress as popularized by Gandhi. In 1921, the British government tried to ban the use of the Gandhi cap. Gandhi himself wore the cap only for 1–2 years during 1920-21

Prisoners in South African prisons classified as “negroes” (a category into which Indians fell while Gandhi was in South Africa) also were required to wear similar caps in prison during 1907 to 1914. Gandhi’s close friend Henry Polak cites Gandhi’s time in South African jail, where he was classified as a “negro” and thus required to wear such a cap, as the genesis of the Gandhi Cap.

In later times, the cap had lost its popular and political appeal.The cap remains the most popular everyday headgear worn by men in rural parts of Maharashtra

Source: http://en.wikipedia.org/wiki/Gandhi_cap